common : implement common_schema internal representation for JSON schemas (#28736)

* common : implement common_schema types

* common : implement a json schema optimizer

* common : reduce optimizations

* common : refactor json-schema-to-grammar to use common_schema

* common : use common_trie

* common/schema : implement type/kind resolution

* cont : cleanup

* cont : remove common_chat_tool_parameters

* cont : simplify schema resolution

* cont : pass common_schema through the json-schema-to-grammar builder

* cont : cleanup

* cont : move enums under common_schema and add type enum

* cont : reduce test cases

* cont : clean up

* cont : clean up

* refactor : rename common_schema_parse to common_schema_from_json

* tests : fix gcc dangling-reference warning in test-json-schema

* tests : take the schema label as const char * to satisfy gcc dangling-reference

* refactor : rename common_schema_builder parse_* methods to build_*

* cont : fix may_be_string

* cont : properly handle empty tool parameters

* cont : add tests for empty $ref

* cont : remove dead code

* cont : update docs

* cont : make "{}" mean any object for json_object as well

* cont : restore (min|max)Length to imply string type

* cont : rename common_schema to common_chat_schema

.github/workflows/build-cpu.yml

@@ -221,7 +221,6 @@ jobs:
       #     7z x "-o${env:RUNNER_TEMP}" $env:RUNNER_TEMP/sde.tar
       #     $sde = $(join-path $env:RUNNER_TEMP sde-external-${env:SDE_VERSION}-win/sde.exe)
       #     cd build
-      #     $env:LLAMA_SKIP_TESTS_SLOW_ON_EMULATOR = 1
       #     & $sde -future -- ctest -L main -C Release --verbose --timeout 900
 
       - name: ccache-clear