Add temporary option to allow suppression of recoverable LSP error toasts

[dibarbet]

Resolves #6977

Add temporary option to suppress LSP recoverable errors until we can resolve the architectural issues causing the failed requests.
Related to #6973, microsoft/vscode-dotnettools#722 and more

Implemented as suggested in microsoft/vscode-languageserver-node#1449 (comment)

Additional notes

1. VSCode's notification settings intentionally do not allow errors to be suppressed.
2. Ideally we could look at VSCode's do not disturb settings or notification settings for the extension instead of our own option, but the API for that does not exist.
3. I considered automatic suppression based duplicate error messages, but unfortunately the data in the exceptions is different enough that there's no simple way to reliably determine if the response error is the 'same' problem. Since this is temporary until we can fix the toasts showing up an option seemed more appropriate.

[Cosifne]

🤔how to know if the error is recoverable LSP error or not?

[Cosifne]

Or is it just suppressing everything for a temp workaround?

[dibarbet]

Any LSP error that doesn't shut down the server is 'recoverable'. If the server shuts down we'll get error toasts from a different code path