Hello, this PR adds a new view to the LSP servers menu for
displaying an LSP server capabilities.
When I work on LSP stuff, quite often I need to check what capabilities
an LSP server has. Currently there is no built-in way for checking that
in Zed, and I have to use [`LSP
DevTools`](https://lsp-devtools.readthedocs.io) project. LSP DevTools
works OK but it works as a proxy between the client and the server, so
setting it up is not that easy in Zed. Zed already has many goodies for
LSP like tracing and RPC messages, so I thought that a simple view with
server capabilities could be useful too. Thanks!
## Some screenshots:
### Ruby LSP

### New menu entry:

Release Notes:
- N/A