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/agent_ui/Cargo.toml

@@ -53,6 +53,7 @@ itertools.workspace = true
 jsonschema.workspace = true
 language.workspace = true
 language_model.workspace = true
+language_models.workspace = true
 log.workspace = true
 lsp.workspace = true
 markdown.workspace = true
@@ -87,6 +88,7 @@ theme.workspace = true
 time.workspace = true
 time_format.workspace = true
 ui.workspace = true
+ui_input.workspace = true
 urlencoding.workspace = true
 util.workspace = true
 uuid.workspace = true