[#2084] feat(core): Add JDBC backend operations for fileset

[xloya]

What changes were proposed in this pull request?

The purpose of this PR is to implement JDBC backend operation for Fileset metadata. Depend on #2384.

Why are the changes needed?

Fix: #2084

How was this patch tested?

Add unit tests to test the fileset metadata ops.

[xloya]

@jerryshao @yuqi1129 @qqqttt123 This PR is also ready for reviews, please take a look when you have time!

[yuqi1129]

I'm okay with the current changes.

[xloya]

@jerryshao @qqqttt123 Do you have some comments for this PR? Thanks.

[qqqttt123]

LGTM except for some questions.

[jerryshao]

I have no further comment, overall LGTM. One follow-up thing we should do is to enable end 2 end test for relational entity store, otherwise it is hard to tell if it works as expected. @xloya can you please do it as a follow-up work?

[jerryshao]

@yuqi1129 can you please also assist @xloya on how to test different entity store end to end. Currently, we hardcoded to use rocksdb, maybe we should make it configurable.

[yuqi1129]

@yuqi1129 can you please also assist @xloya on how to test different entity store end to end. Currently, we hardcoded to use rocksdb, maybe we should make it configurable.

Got it.

[xloya]

I have no further comment, overall LGTM. One follow-up thing we should do is to enable end 2 end test for relational entity store, otherwise it is hard to tell if it works as expected. @xloya can you please do it as a follow-up work?

Okay, I will add end-to-end testing of this piece soon.

[qqqttt123]

I have no further suggestion.

[yuqi1129]

LGTM, I'm going to merge it.