Support multiple OpenAI compatible providers (#34212)

TODO
- [x] OpenAI Compatible API Icon
- [x] Docs
- [x] Link to docs in OpenAI provider section about configuring OpenAI
API compatible providers

Closes #33992

Related to #30010

Release Notes:

- agent: Add support for adding multiple OpenAI API compatible providers

---------

Co-authored-by: MrSubidubi <dev@bahn.sh>
Co-authored-by: Danilo Leal <daniloleal09@gmail.com>

crates/language_models/Cargo.toml

@@ -26,10 +26,10 @@ client.workspace = true
 collections.workspace = true
 component.workspace = true
 credentials_provider.workspace = true
+convert_case.workspace = true
 copilot.workspace = true
 deepseek = { workspace = true, features = ["schemars"] }
 editor.workspace = true
-fs.workspace = true
 futures.workspace = true
 google_ai = { workspace = true, features = ["schemars"] }
 gpui.workspace = true