Support json_extract function in UPDATE statement

[yixinglu]

refer https://discuss.nebula-graph.com.cn/t/topic/12592

[wey-gu]

@yixinglu update now cannot take variables/be in pipeline, this is a quite high-demand feature as we don't support merge like expression, could we also support this together with this?

#2938

[xtcyclist]

It's not json_extract that is not supported. It's Expression::Kind::kSubscript . Not sure whether we could lift this ban. This may not be counted as a bug.

I'm advisiting not to lift this ban. I think kSubscript isn't ok for update. An update better carries what it want to change explicitly.

std::unordered_set<Expression::Kind> invalidExprs{
      Expression::Kind::kVersionedVar,
      Expression::Kind::kVarProperty,
      Expression::Kind::kInputProperty,
      // Expression::Kind::kLabelAttribute, valid only for update edge
      Expression::Kind::kSubscript,
      Expression::Kind::kUUID,
      Expression::Kind::kTagProperty,
      Expression::Kind::kLabelTagProperty,
      Expression::Kind::kDstProperty,
      Expression::Kind::kEdgeSrc,
      Expression::Kind::kEdgeType,
      Expression::Kind::kEdgeRank,
      Expression::Kind::kEdgeDst,
  };

[yixinglu]

I think it's a bug, we'd better to fix it since user could not use pipe and variable to update and there's no other way to meet their needs.