Implementation for #2306

Description

This PR adds wildcard (*) support to the On-Demand API's JSONPath functionality, enabling queries that return multiple matching values. Implements wildcards for both objects (.*) and arrays ([*]), including nested and combined wildcards. Includes comprehensive test suite with 12 test cases covering various scenarios.

Type of change

• Bug fix
• New feature
• Refactor / cleanup
• Documentation / tests
• Other (please describe):

Run tests:

cd build
cmake -B build -D SIMDJSON_SANITIZE=ON -D SIMDJSON_DEVELOPER_MODE=ON
cmake --build build
ctest --test-dir build --output-on-failure
# Or specific test:
./build/tests/ondemand/ondemand_wildcard_tests