[FEATURE] how to implement metadata search?

### Describe the feature

I want to know if gravitino has any plans to implement metadata search,for example table search.
Gravitino use kv as the storage and has stored table metadata 。but I dont't know how to implement metadata search.kv storage don't supply the function of search。
Do I have to replace it with other storage？
Are there any ideas for implementing table search？

### Motivation

_No response_

### Describe the solution

_No response_

### Additional context

_No response_

No files, tests, or entry points are named. Start by reviewing Gravitino’s existing KV-backed table-metadata storage and metadata APIs, then determine how table search could be supported without assuming a storage replacement. Done should include a decided search approach and a clear implementation scope.

Written by the indexing model from the issue text.