feat(tools): support Tool calls in the API (#1715)

* feat(tools): support Tools in the API

Co-authored-by: =?UTF-8?q?Stephan=20A=C3=9Fmus?= <stephan.assmus@sap.com>

* feat(tools): support function streaming

* Adhere to new return types when using tools instead of functions

* Keep backward compatibility with function calling

* Evaluate function names in chat templates

* Disable recovery with --debug

* Correctly stream out the entire result

* Detect when llm chooses to reply and to not perform any action in SSE

* Feedback from code review

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Co-authored-by: =?UTF-8?q?Stephan=20A=C3=9Fmus?= <stephan.assmus@sap.com>