[VL] OAP velox commits track

### Description

Current velox commits in oap/velox:

- [ ] [[5962 ] Support struct column reading with different schemas (5962)]
- [ ] [[6020 ] Spark sql avg agg function support decimal]
- [ ] [[oap1] Register merge extract companion agg functions without suffix]
- [ ] [[oap2] Treat timestamp partition value as UTC]
- [ ] [[oap3] Delete website folder due to security issues
- [ ] [[oap4] Set writeInt96AsTimestamp to true, will remove after int64 sup…]
- [ ] [[oap5] Support scan filter for decimal in ORC]
- [ ] [[oap6] fix unit tests]
- [x] [[11691] feat: Add get_json_object Spark function]
- [ ] [[oap7] adding simdjson/gflags changes]

3 has PRs in upstream velox
7 no PR submitted yet

Review the checklist and the referenced upstream Velox commits first; the issue names no repository files or tests. Done means determining the status of each unchecked item and completing or tracking the seven items without submitted upstream pull requests.

Written by the indexing model from the issue text.