Add OCaml support (#6929)

This pull request implements support for the [OCaml
Language](https://ocaml.org/).

### Additions
- [x]
[tree-sitter-ocaml](https://github.com/tree-sitter/tree-sitter-ocaml)
grammar
- [x] Highlight, Indents, Outline queries
- [x] A new file icon for .ml(i) files. Based on
[ocaml/ocaml-logo](https://github.com/ocaml/ocaml-logo/blob/master/Colour/SVG/colour-transparent-icon.svg)
- [x] LSP Integration with
[ocaml-language-server](https://github.com/ocaml/ocaml-lsp)
- [x] Completion Labels
- [x] Symbol Labels

### Bug Fixes
- [x] Improper parsing of LSP headers. 

### Missing [will file a separate issue]
- Documentation on completionItem, requires: `completionItem/resolve`
with support for `documentation` as a provider.

### Screenshots

<details><summary>Zed</summary>
<img width="1800" alt="Screenshot 2024-02-01 at 03 33 20"
src="https://github.com/zed-industries/zed/assets/69181766/e17c184e-203e-40c3-a08f-4de46226b79c">
</details>

Release Notes:
- Added OCaml Support
([#5316](https://github.com/zed-industries/zed/issues/5316)).

> [!NOTE]
> Partially completes #5316 
> To complete #5316:
> 1. addition of a reason tree-sitter grammar.
> 2. opam/esy integration, however it may be better as it's own plugin.

crates/zed/Cargo.toml

@@ -130,6 +130,7 @@ tree-sitter-lua.workspace = true
 tree-sitter-markdown.workspace = true
 tree-sitter-nix.workspace = true
 tree-sitter-nu.workspace = true
+tree-sitter-ocaml.workspace = true
 tree-sitter-php.workspace = true
 tree-sitter-proto.workspace = true
 tree-sitter-purescript.workspace = true