chore: refactor test scripts

[techfg]

What does this PR do?

Refactors and improve tests scripts and test execution:

1. Modularizes test scripts for re-usability
2. Ensures test suites complete successfully when run in isolation (e.g., e2e no longer requires integration to have run)
3. Moves ssl setup out of docker test runs to avoid potential interactive prompts due to sudo
4. Ensures all test related apps/workspaces/sites/data is fully removed after each test run
5. Ensures latest code is built prior to creating docker image for tests
6. Updates docs to align with current test process/scripts/etc.
7. Uses environment variables throughout all tests to avoid hardcoded values in multiple places
8. updates npm scripts in package.json
9. Changes nomenclature of tests-ci to tests-docker since ci workflows actually run unit/integration/e2e while tests-ci script only ran integration/e2e.
10. Standardizes naming convention/format of all test related scripts to *-tests.sh (e.g., previously was mixture of *-tests & tests-*).

Resolves #4574

Testing

All tests pass locally, ci workflow will test everything to make sure.