feature: table branching

[BohuTANG]

Summary

Create branching:

ALTER TABLE db.table CREATE BRANCH test_branch;

Query branching:

SELECT * FROM db.table VERSION AS OF 'test_branch';
1   a   1.0
2   b   2.0
3   c   3.0

List branchings:

SELECT * FROM db.table.refs;
test_branch BRANCH  8109744798576441359 NULL    NULL    NULL
main        BRANCH  6910357365743665710 NULL    NULL    NULL


SELECT * FROM db.table VERSION AS OF 8109744798576441359;
1   a   1.0
2   b   2.0
3   c   3.0

Merge branching:

ALTER TABLE db.table MERGE BRANCH test_branch INTO main [DRY RUN];

Reference: https://iceberg.apache.org/docs/latest/branching/