Fix build for #7711 after #7710 refactoring

[bbrks]

• Fix build for CBG-4785: sendChanges support for legacy rev #7711 after CBG-4787 move SyncData.HLV to Document.HLV #7710 refactoring
• Rename variable mentioned but accepted in original CBG-4785: sendChanges support for legacy rev #7711 PR merge
• Change function signature for future intended usage (return type as well as value)

Integration Tests

• n/a

[Copilot]

Pull Request Overview

This PR fixes build issues that resulted from refactoring in #7710 by updating method calls and function signatures. The changes rename variables for clarity and modify a function to return additional type information for future usage.

• Replace deprecated doc.CurrentRev calls with doc.GetRevTreeID() method calls
• Rename and modify GetChangeEntryVersion() to GetChangeRowRev() with enhanced return type
• Update caller to handle the new function signature

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
db/utilities_hlv_testing.go	Updates method calls from CurrentRev field to GetRevTreeID() method
db/changes.go	Renames function and modifies signature to return version type alongside version string
db/blip_handler.go	Updates caller to handle new function signature with additional return value