tool-call: refactor common chat / tool-call api (+ tests / fixes) (#11900)

tool-call: refactor common chat / tool-call api (+ tests / fixes) (#11900)

* tool-call refactoring: moved common_chat_* to chat.h, common_chat_templates_init return a unique_ptr to opaque type

* addressed clang-tidy lints in [test-]chat.*

* rm minja deps from util & common & move it to common/minja/

* add name & tool_call_id to common_chat_msg

* add common_chat_tool

* added json <-> tools, msgs conversions to chat.h

* fix double bos/eos jinja avoidance hack (was preventing inner bos/eos tokens)

* fix deepseek r1 slow test (no longer <think> opening w/ new template)

* allow empty tools w/ auto + grammar

* fix & test server grammar & json_schema params w/ & w/o --jinja