language support: CodeQL

[evanrichter]

adds CodeQL support for highlighting, text objects, and LSP!

the treesitter grammer defines the language as just ql (thus exporting the function tree_sitter_ql in the dylib) but I've never heard it referred by just that, it's always "CodeQL", so I stuck with "codeql" for all user facing names for this language.

For code fences in markdown, github supports this language as codeql or ql, but again, I don't think anyone refers to this language as just ql, so I left the injection-regex as codeql.

For the language server, it works as defined, but minimally. Formatting works, goto definition, etc. But to be actually useful, users will probably need to override the args to add --search-path=P where P is a path to their local checkout of the standard queries. It would be nice to have an lsp option for appending args to the default like this:

# ideally:
[language-servers.codeql]
extraArgs = ["--search-path=P"] # just the appended args

# current users need to respecify default args:
[language-servers.codeql]
args = ["execute", "language-server", "--check-errors=ON_CHANGE", "--search-path=P"]