Alignment of Default Class Implementations to Interface definitions

[snarkipus]

Resolves #1584

Summary:

• Added cancellation token support to various language server protocol (LSP) methods, allowing operations to be interrupted.
• Updated method signatures across multiple LSP providers (e.g. completion, definition, document highlight) with updated documentation and optional parameters.
• Implemented default no-op implementations for several DocumentUpdateHandler methods to reduce boilerplate in subclasses.
• Refactored several methods to use optional parameters with default values instead of explicitly passing default values, improving code readability.

[spoenemann]

Thank you! Most of the changes look good to me.

However, I'm not convinced of these:

• Implemented default no-op implementations for several DocumentUpdateHandler methods to reduce boilerplate in subclasses.
• Refactored several methods to use optional parameters with default values instead of explicitly passing default values, improving code readability.

[msujew]

Looks good, just a few minor changes, see below.

[msujew]

Looks good to me, thanks 👍