[goose-llm] add generate tooltip & session name via extract method (#2467)

* extract method in provider to use for structured outputs

* generate session name from msgs

* generate tooltip from msgs

* add provider tests

crates/goose-llm/src/providers/errors.rs

@@ -22,6 +22,9 @@ pub enum ProviderError {
 
     #[error("Usage data error: {0}")]
     UsageError(String),
+
+    #[error("Invalid response: {0}")]
+    ResponseParseError(String),
 }
 
 impl From<anyhow::Error> for ProviderError {