[core] Fix scan from tag on branch table.

[Stephen0421]

Purpose

Fix batch read from tag on branch tables. StaticFromTagStartingScanner creates TagManager without branch name, so tags that exist only on a branch cannot be resolved and reads with scan.tag-name fail with Tag doesn't exist.

Pass snapshotManager.branch() when creating TagManager, consistent with AbstractBatchTableScan, AbstractDataTableScan, and IncrementalDiffStartingScanner.

Test

• Add testGetSnapshotFromBranchTag and testScanFromBranchTag in StaticFromTagStartingScannerTest

[JingsongLi]

+1