Add progress or busy indication when extension is formatting.

[karthiknadig]

Based on input from @Bobronium

This is definitely possible with the Progress APIs for LSP.
We just need to set workDoneProgress: True as the option when we register the Formatting feature @LSP_SERVER.feature
https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#documentFormattingOptions

Then in the params handle the progress token and respond accordingly to those params.
https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#clientInitiatedProgress

[agnes-sharan]

Hi is this issue still open for contribution?

[karthiknadig]

@agnes-sharan Go ahead.