Remove single-{ handling entirely - jinja across the board

[mattgodbolt]

There are several changes in this PR which you can look at individually:

1. Work to add a ce_install config-dump command which dumps a sequence of JSON lines of the entire expanded configuration of everything.
2. A change where (carefully) all the { were turned into jinja {{ and }} etc. At various stages of this change, and most importantly at the end, the output of ce_install config-dump was compared and no actual config changes occurred.
3. The ability to use single { was removed from the config loader, and tests updated and added.

This should allow single quotes to be used as normal, and in some cases {% raw %} type things (though this is not perfect for that, we may need more work, I have ideas on how to fix that but let me know if this is enough to start with @partouf.

Some junky editor config (both from intellij and vscode) made it into the change too, I can extract if it's annoying.

Example of the first few lines of the config dump output:

{"name": "compilers/ada/gnat/arm 10.3.0-2", "type": "TarballInstallable(compilers/ada/gnat/arm 10.3.0-2, arm/gnat-arm-elf-linux64-10.3.0-2)", "config": {"check_file": "", "install_path": "arm/gnat-arm-elf-linux64-10.3.0-2", "language": "ada", "name": "compilers/ada/gnat/arm 10.3.0-2", "remove_older_pattern": "", "target_name": "10.3.0-2", "untar_path": "gnat-arm-elf-linux64-10.3.0-2", "untar_to": ".", "url": "https://github.com/alire-project/GNAT-FSF-builds/releases/download/gnat-10.3.0-2/gnat-arm-elf-linux64-10.3.0-2.tar.gz"}}
{"name": "compilers/ada/gnat/arm 11.2.0-3", "type": "TarballInstallable(compilers/ada/gnat/arm 11.2.0-3, arm/gnat-arm-elf-linux64-11.2.0-3)", "config": {"check_file": "", "install_path": "arm/gnat-arm-elf-linux64-11.2.0-3", "language": "ada", "name": "compilers/ada/gnat/arm 11.2.0-3", "remove_older_pattern": "", "target_name": "11.2.0-3", "untar_path": "gnat-arm-elf-linux64-11.2.0-3", "untar_to": ".", "url": "https://github.com/alire-project/GNAT-FSF-builds/releases/download/gnat-11.2.0-3/gnat-arm-elf-linux64-11.2.0-3.tar.gz"}}
{"name": "compilers/ada/gnat/riscv64 10.3.0-2", "type": "TarballInstallable(compilers/ada/gnat/riscv64 10.3.0-2, riscv64/gnat-riscv64-elf-linux64-10.3.0-2)", "config": {"check_file": "", "install_path": "riscv64/gnat-riscv64-elf-linux64-10.3.0-2", "language": "ada", "name": "compilers/ada/gnat/riscv64 10.3.0-2", "remove_older_pattern": "", "target_name": "10.3.0-2", "untar_path": "gnat-riscv64-elf-linux64-10.3.0-2", "untar_to": ".", "url": "https://github.com/alire-project/GNAT-FSF-builds/releases/download/gnat-10.3.0-2/gnat-riscv64-elf-linux64-10.3.0-2.tar.gz"}}
{"name": "compilers/ada/gnat/riscv64 11.2.0-3", "type": "TarballInstallable(compilers/ada/gnat/riscv64 11.2.0-3, riscv64/gnat-riscv64-elf-linux64-11.2.0-3)", "config": {"check_file": "", "install_path": "riscv64/gnat-riscv64-elf-linux64-11.2.0-3", "language": "ada", "name": "compilers/ada/gnat/riscv64 11.2.0-3", "remove_older_pattern": "", "target_name": "11.2.0-3", "untar_path": "gnat-riscv64-elf-linux64-11.2.0-3", "untar_to": ".", "url": "https://github.com/alire-project/GNAT-FSF-builds/releases/download/gnat-11.2.0-3/gnat-riscv64-elf-linux64-11.2.0-3.tar.gz"}}
{"name": "compilers/nightly/dex2oat dex2oat-latest", "type": "ScriptInstallable(compilers/nightly/dex2oat dex2oat-latest, dex2oat-latest)", "config": {"check_file": "x86_64/bin/dex2oat64", "install_path": "dex2oat-latest", "language": "nightly", "name": "compilers/nightly/dex2oat dex2oat-latest", "script": "mkdir dex2oat-latest\ncd dex2oat-latest\n/home/matthew/dev/ce/infra/bin/yaml/android-java/fetch_art_release_from_head.sh\nunzip art_release.zip\nrm art_release.zip\n/home/matthew/dev/ce/infra/bin/yaml/android-java/create_boot_images.sh", "target_name": "dex2oat-latest"}}
{"name": "compilers/android-d8 8.1.56", "type": "SingleFileInstallable(compilers/android-d8 8.1.56, r8-8.1.56)", "config": {"check_file": "", "filename": "r8-8.1.56.jar", "install_path": "r8-8.1.56", "language": "android-d8", "name": "compilers/android-d8 8.1.56", "target_name": "8.1.56", "url": "https://dl.google.com/android/maven2/com/android/tools/r8/8.1.56/r8-8.1.56.jar"}}
{"name": "compilers/android-d8 8.1.72", "type": "SingleFileInstallable(compilers/android-d8 8.1.72, r8-8.1.72)", "config": {"check_file": "", "filename": "r8-8.1.72.jar", "install_path": "r8-8.1.72", "language": "android-d8", "name": "compilers/android-d8 8.1.72", "target_name": "8.1.72", "url": "https://dl.google.com/android/maven2/com/android/tools/r8/8.1.72/r8-8.1.72.jar"}}
{"name": "compilers/android-d8 8.2.33", "type": "SingleFileInstallable(compilers/android-d8 8.2.33, r8-8.2.33)", "config": {"check_file": "", "filename": "r8-8.2.33.jar", "install_path": "r8-8.2.33", "language": "android-d8", "name": "compilers/android-d8 8.2.33", "target_name": "8.2.33", "url": "https://dl.google.com/android/maven2/com/android/tools/r8/8.2.33/r8-8.2.33.jar"}}
{"name": "compilers/android-d8 8.2.42", "type": "SingleFileInstallable(compilers/android-d8 8.2.42, r8-8.2.42)", "config": {"check_file": "", "filename": "r8-8.2.42.jar", "install_path": "r8-8.2.42", "language": "android-d8", "name": "compilers/android-d8 8.2.42", "target_name": "8.2.42", "url": "https://dl.google.com/android/maven2/com/android/tools/r8/8.2.42/r8-8.2.42.jar"}}
{"name": "compilers/android-d8 8.2.47", "type": "SingleFileInstallable(compilers/android-d8 8.2.47, r8-8.2.47)", "config": {"check_file": "", "filename": "r8-8.2.47.jar", "install_path": "r8-8.2.47", "language": "android-d8", "name": "compilers/android-d8 8.2.47", "target_name": "8.2.47", "url": "https://dl.google.com/android/maven2/com/android/tools/r8/8.2.47/r8-8.2.47.jar"}}

To repro you can:

$ git checkout be49fae707c516553b108a72f2859ac3070a7927
$ ce_install config-dump /tmp/before
$ git checkout 50e3cc1b9fd8b7f02b73d0e50248de20d18a3a7e
$ ce_install config-dump /tmp/after
$ diff /tmp/before /tmp/after
$

[mattgodbolt]

See #1476