[#2252][#2253][#2470] (PyClient): Add Fileset APIs in Gravitino Python client

[xunliu]

What changes were proposed in this pull request?

Support Fileset Catalog in Python client, support below functions:

1. list_filesets()
2. load_fileset()
3. create_fileset()
4. alter_fileset()
5. drop_fileset()

Why are the changes needed?

Fix: #2470 #2252 #2253

Does this PR introduce any user-facing change?

N/A

How was this patch tested?

CI Passed

[shaofengshi]

This interface will be changed soon(plan in 0.6, see #553 and #2479); I'm not suggesting to implement it now in Python.

[xunliu]

When we create Fileset catalog or do other operations, We need create metalake and schema before that, Because Fileset catalog dependence metalake and schema.
So I need implement SupportsSchemas, I don't wait 0.6 version.

[shaofengshi]

I think this PR has too many changes; Some code like the ChangeRequest, SupportsSchemas are not needed at this moment; If we add them, need to ensure the API's stable, and the functionality are all ready to use (need UT);

Besides, as the implementation are from Java client, I have the concern that it is not the best way of using in Python. Need be evaluated and get feedback from real Python scenarios.

[xunliu]

I think this PR has too many changes; Some code like the ChangeRequest, SupportsSchemas are not needed at this moment; If we add them, need to ensure the API's stable, and the functionality are all ready to use (need UT);

Besides, as the implementation are from Java client, I have the concern that it is not the best way of using in Python. Need be evaluated and get feedback from real Python scenarios.

Because if we need implement Fileset Catalog, We must implement Metalake and schema operation. because Fileset Catalog depends Metalake and schema.
All my test cases are done, waiting for this PR to be merged and submitted.

[xunliu]

The code I'm about to commit depends on this PR and I've been waiting for this PR merge for 2 days now, so I'm merging this PR first. If there is a problem, we can create a new issue to discuss it.