feat(upgrade): add ability to provide a startingOffset for RestoreIndices

[ukayani]

Running the RestoreIndices on a slow DB or a very large table can take a long time -- this change is intended to allow resuming at a particular startingOffset.

• Modified the RestoreIndices job to accept an optional startingOffset param which gets propagated to the RestoreIndicesArgs start property

Checklist

• [ x] The PR conforms to DataHub's Contributing Guideline (particularly Commit Message Format)
• [x ] Links to related issues (if applicable)
• [x ] Tests for the changes have been added/updated (if applicable)
• [ x] Docs related to the changes have been added/updated (if applicable). If a new feature has been added a Usage Guide has been added for the same.
• [ x] For any breaking change/potential downtime/deprecation/big changes an entry has been made in Updating DataHub

[david-leifker]

LGTM! Thanks!