Ask user for permission to start a LSP server

ATM we start stuff without asking the user if that is ok.

This request allows the user to allow/block the starts (for once or permanent) and one has a minimal UI to later adjust the allow/block state.

This IMHO makes it more "secure" as no stuff will be launched without at least one review and in addition allows the user to easily block server starts that e.g. fail on their machine without messing with the LSP json file.