ollama: Add tool call support (#29563)

The goal of this PR is to support tool calls using ollama. A lot of the
serialization work was done in
https://github.com/zed-industries/zed/pull/15803 however the abstraction
over language models always disables tools.

## Changelog:

- Use `serde_json::Value` inside `OllamaFunctionCall` just as it's used
in `OllamaFunctionCall`. This fixes deserialization of ollama tool
calls.
- Added deserialization tests using json from official ollama api docs.
- Fetch model capabilities during model enumeration from ollama provider
- Added `supports_tools` setting to manually configure if a model
supports tools

## TODO:

- [x] Fix tool call serialization/deserialization
- [x] Fetch model capabilities from ollama api
- [x] Add tests for parsing model capabilities 
- [ ] Documentation for `supports_tools` field for ollama language model
config
- [ ] Convert between generic language model types
- [x] Pass tools to ollama

Release Notes:

- N/A

---------

Co-authored-by: Antonio Scandurra <me@as-cii.com>
Co-authored-by: Nathan Sobo <nathan@zed.dev>

crates/assistant_settings/src/assistant_settings.rs

@@ -315,7 +315,12 @@ impl AssistantSettingsContent {
                                 _ => None,
                             };
                             settings.provider = Some(AssistantProviderContentV1::Ollama {
-                                default_model: Some(ollama::Model::new(&model, None, None)),
+                                default_model: Some(ollama::Model::new(
+                                    &model,
+                                    None,
+                                    None,
+                                    language_model.supports_tools(),
+                                )),
                                 api_url,
                             });
                         }