derived SqlNode/PlanNode/... may incomplete due to missing override for `Equals` method

e.g
- DeployPlanNode: https://github.com/4paradigm/openmldb/blob/836b34119249ff9b667130b125c88395ef18ee4f/hybridse/include/node/plan_node.h#L477
- DeployNode: https://github.com/4paradigm/openmldb/blob/836b34119249ff9b667130b125c88395ef18ee4f/hybridse/include/node/sql_node.h#L2207

_Originally posted by @aceforeverd in https://github.com/4paradigm/OpenMLDB/pull/1283#discussion_r811867541_

The issue points to two derived classes (DeployPlanNode and DeployNode) in hybridse/include/node/plan_node.h and sql_node.h that may be missing overrides for the `Equals` method. First, examine the base class hierarchy to understand the expected `Equals` signature and semantics. Then, check if other derived classes provide overrides as examples. Implement the missing overrides, ensuring they compare all relevant member variables. Run existing tests related to node equality to verify correctness.

Written by the indexing model from the issue text.