[Java] Implement hash table and equals & hashCode API for dictionary encoding #22315
Description
As discussed in #4792
Implement a hash table to only store hash & index, meanwhile add check equal function in ValueVector API.
Reporter: Ji Liu / @tianchen92
Assignee: Ji Liu / @tianchen92
PRs and other links:
Note: This issue was originally created as ARROW-5902. Please see the migration documentation for further details.