feat(vscode): Add Language Status Item

[spotandjake]

This adds a languageStatusItem to the vscode extension VSCODE Status Item specifically this provides a place for us to list the grain extension commands and display stats about the server.

This pr also contributes a new openOutput command which opens the grain extension output window.

The statusBar item currently only shows an error severity when the lsp crashes out. But we can extend the functionality in the future similar to how rescript tracks status here and have it show things such as if the lsp is busy during formatting.

[ospencer]

Do we really need a command to show the output? That feels like something just for people developing the LSP rather than the average user.

[spotandjake]

Do we really need a command to show the output? That feels like something just for people developing the LSP rather than the average user.

It mostly is useful for when developing but I was going off what the eslint extension had in their status item and given its a place that shows the current lsp status such as if it is not working I think it makes sense for the logs to be easily accessible from it.