Code Actions on save

[archseer]

Discussed in #1540

^{Originally posted by kevinsjoberg January 19, 2022}
Helix currently supports running Code Actions manually by pressing <space>+a. Some language servers also supports running specific code actions on save, e.g., typescript-language-server and gopls.

Preferably, we extend the language server configuration to allow for specifying code actions to run on save. The actions themselves would then run asynchronously, similar to what we already do for auto formatting.

[archseer]

The VSCode config seems to be:

"[go]": {
    "editor.codeActionsOnSave": {
        "source.organizeImports": true
    }
},

source.organizeImports and now source.sortImports (https://code.visualstudio.com/updates/v1_57#_sort-imports-source-action) seem to be the standardized name for this behavior and could be auto-enabled if the LSP offers them.