Add CMP_WILDCARD string comparator for ? and * pattern matching

[natitsechanski]

• Add CMP_WILDCARD string comparator supporting ? (single char) and * (any chars) wildcard matching
• Iterative implementation in C runtime — no recursion, safe on pathological input
• Wired across FlatBuffers schema, C runtime, generated headers, Go schema, and JSON schema
• Unit tests covering NULL handling, ?, *, mixed patterns, RFC-style paths, and backtracking edge cases

Test plan

• make -C c test — all 55 tests pass
• Coverage unchanged or improved on /work/c/src

[annacai21]

Could you update arguments.go so wildcard patterns in the args use CmpTypeSTRCMP_WILDCARD like the commands?