intellisense for code actions on save

[justschen]

fixes #161284
related #212381

issue: no intellisense because of how we get contributed or default code actions on save
https://github.com/justschen/vscode/blob/a6bda062d6a861071758ded8abc781af37a083e2/src/vs/workbench/contrib/codeActions/common/codeActionsExtensionPoint.ts#L69

atm, we only search contributions if they statically contribute code actions (ie, https://github.com/justschen/vscode/blob/a6bda062d6a861071758ded8abc781af37a083e2/extensions/typescript-language-features/package.json#L1608-L1609)

this allows us to gather ALL code actions that are contributed, sorts by source actions, dynamically adds

demo with ruff and eslint installed:

cc. @Yoyokrazy

[justschen]

Also as part of documentation, we could maybe note that if there are two of source actions of the same type, but one is a subset of another, only the larger subset would be honored (wording and terms can be better)

ie:

"editor.codeActionsOnSave": {
       "source.fixAll": "explicit",
       "source.fixAll.eslint": "never"

in this case, source.fixAll will override source.fixAll.eslint.

[mjbvz]

looks good! I think you should also remove the static contribution tho. This was a proposal that I never actually finalized

One other thing to be aware of is that this intellisense will only pick up code actions for active languages. This at least ensures that only valid source actions are shown, but could also confuse users if they try configuring the setting without activating the language extension first (that's what the static contribution was trying to solve)

You could potentially solve this by caching the source actions for each extension across restarts. May be worth tracking in a new issue