CQ: Add .editorconfig and validate repo against it

[echoix]

To be rebased after #4790 and #4791, to drop repeated commits. This is intended to be a draft, and would like to separate the change of line endings stored to CRLF for some files (plus the .gitattributes file change) to be in another commit, easier to cherry-pick afterwards.

With an .editorconfig file, most editors will adjust some preferences to match these settings. For example, setting to trim lines on some file types will have the whitespace trimmed when saving the file, preventing the situation where I regularly need to remove some files that slept through, as we had no CI to enforce it. Setting whether spaces or tabs are used, the indent size, whether to always ensure a new line is present on save. Plugins can accept more domain-specific settings, but appart from the couple of basic properties that are supported by all implementations, the rest is more like a preference if the plugins support the custom properies. For example, Intellij (Pycharm) uses many keys supported only by them, and in CSharp+Visual Basic, editorconfig files are used to select ALL the formatting choices and enable/silence/change the severity of some warnings, supported with more than just the Visual Studio IDE.

This PR:

• Sets up an .editorconfig file https://editorconfig.org/. Some rules will need to be introduced later on, as too many files are affected at once
• Uses editorconfig-checker to check in CI (through super-linter) and with pre-commit.
• Creates a .gitattributes file to ensure Git normalizes some files, like .bat and .cmd as CRLF no matter what the platform is. https://git-scm.com/docs/gitattributes
• Fixes some files so that editorconfig-checker would not fail the run.

[echoix]

Theres 7 bat files to change line endings too