Install VSCodium and make host .application file

[justinmichaud]

• Allow installing VSCodium
• Add helpful clangd default settings
• Make VSCode .application file by default

[justinmichaud]

Thank you for the review, everything has been updated!

[justinmichaud]

I have simplified this PR:

• We always use the tar version of vscode or vscodium, so that this can work for armv7, arm64 and x64
• Only the settings that were not contentious are set
• I got rid of a bunch of duplicated code.

This is tested and working on arm64 and armv7

[nikolaszimmermann]

@justinmichaud ok to merge as-is? Could you verify once again this is still working fine?
@TingPing can you have another look? Let's get this off the review queue :-)

[TingPing]

We always use the tar version of vscode or vscodium, so that this can work for armv7, arm64 and x64

This is problematic. The deb does more things such as installing an apt repo for updates. I don't think they are the same binaries either.