* Add search implementation in ExecutionEngine
Signed-off-by: Nfishpenguin <kun.yu@zilliz.com>

* Remove attr_type from query_ptr
Signed-off-by: Nfishpenguin <kun.yu@zilliz.com>

* Add CreateStructuredIndex in ExecutionEngine
Signed-off-by: Nfishpenguin <kun.yu@zilliz.com>

* Add index fields in QueryPtr
Signed-off-by: Nfishpenguin <kun.yu@zilliz.com>

* Fix SearchReq bugs
Signed-off-by: Nfishpenguin <kun.yu@zilliz.com>

* code format
Signed-off-by: Nfishpenguin <kun.yu@zilliz.com>

* Add Search in scheduler
Signed-off-by: Nfishpenguin <kun.yu@zilliz.com>

* Fix SearchJob and SearchTask
Signed-off-by: Nfishpenguin <kun.yu@zilliz.com>

* Add MergeTopkResultSet
Signed-off-by: Nfishpenguin <kun.yu@zilliz.com>

* Remove nq in VectorQuery
Signed-off-by: Nfishpenguin <kun.yu@zilliz.com>

* Change segment_size to segment_row_count in C++ sdk
Signed-off-by: Nfishpenguin <kun.yu@zilliz.com>

* Fix row_count in Search
Signed-off-by: Nfishpenguin <kun.yu@zilliz.com>
Co-authored-by: NWang XiangYu <xy.wang@zilliz.com>