feat(lsp): added support for dynamic capabilities

[folke]

Description

Added support for dynamic registration of capabilities to all the lsp pickers.
I also refactored the relevant code a bit to make it less verbose.

Any code that wants to check lsp capabilities should use client.supports_method.
That function includes checks for dynamically registered capabilities.
Just checking server_capabilities only includes caps that were advertised during init.

Fixes LazyVim/LazyVim#990

Fixes goto definition for a number of lsp servers like jdtls and solargraph

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

I've testes all the methods using several LSP servers including the one solargraph where go to definition was broken.

Checklist:

• My code follows the style guidelines of this project (stylua)
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation (lua annotations)

[folke]

The failing tests are not because of this change, but because homebrew can not be updated

[tjdevries]

Thanks, makes sense to me. Some of that LSP code is quite old (not all the methods existed at the time). Thanks :)

[ben-krieger]

Is there a reason that this commit hasn't been cherry-picked into a release (of which there have been a few since the PR was merged)? The README discourages using master, but as a user of jdtls, I need this fix for jumping to definition to work.

[jamestrew]

@ben-krieger we aren't cherry picking features into 0.1.x following semver. This will come in 0.2.0 but no timeline for this.
Best bet is using the master branch pinned to this commit.