Add sandbox setup cmd for VSCodium

[rinOfTheStars]

This implicitly requires vscode-tree-sitter-query to be published to the Open VSX Registry to not cause issues when running tests, as rn that plugin is commented out in packages/common/src/extensionDependencies.ts due to it not being present there. This PR will therefor need to be a draft until that plugin is uploaded to Open VSX; I'll probably also add to the documentation to note the differences in commands between VSCodium and VSCode at some point soon. There's also probably a cleaner way to do this with a variable passed to packages/cursorless-vscode/src/scripts/initLaunchSandbox.ts to swap between vscode and vscodium mode or something, but I'll look into that later as well.

[rinOfTheStars]

The only reliable, cross-platform workaround to OpenVSX marketplace not having the vscode-tree-sitter-query plugin I could find was to just bundle it as part of the repository (in data/vsix for now) as a vsix file. Afaik this should work with the filesystems of all OSes supported by Talon (Windows, macOS, Linux).

I'll add some details to the documentation about this, and then things should be ready for review!

[rinOfTheStars]

Should be ready for review!

[AndreasArvidsson]

Not quite sure I'm following fully. The parse tree extension that Cursorless requires is already available on open vsx.
https://open-vsx.org/extension/pokey/parse-tree

[rinOfTheStars]

Not quite sure I'm following fully. The parse tree extension that Cursorless requires is already available on open vsx.

https://open-vsx.org/extension/pokey/parse-tree

jrieken:vscode-tree-sitter-query (https://github.com/jrieken/vscode-tree-sitter-query) is the extension, not pokey:parse-tree. It's the syntax highlighter/file support provider for the tree sitter query language, so it's included in extensionDependencies.ts, and required since the query language is a language supported by Cursorless

[AndreasArvidsson]

Oh you mean you are missing a language definition for .scm files?

I'm not a big fan of bundling other extensions like this. Is it really that much of a problem to just install this dependency manually during initial setup for now? Hopefully the extension will be available on the marketplace in the future