feat: remove javascript from exception pages (#33)

* feat: remove javascript from exception pages

this allows the exceptions to be fully inspected in the preview panes of browsers and postman

* restore the `extra_javascript` support

* fix styles for desktop view

* fix mobile styles

* add some whitespace

* fix line under stack-trace-heading

* improve mobile view

* fix set version

using the macro to maintain compatibility with [wyhaines/defined.cr](https://github.com/wyhaines/defined.cr#version-checks)

* don't add script tag unless extra_javascript is provided

* fix mobile logo placement

* reset margin when logo hidden

* simplify version definition

* remove downcase

Co-authored-by: Sijawusz Pur Rahnama <[email protected]>

Co-authored-by: Sijawusz Pur Rahnama <[email protected]>

Author: stakach