feat: Add query-time offset parameter for predefined granularities (implements #10042)

[hank-sq]

Check List

• [X] Tests have been run in packages where changes have been made if available
• [ ] Linter has been run for changed code
• [X] Tests for the changes have been added if not covered yet
• [ ] Docs have been added / updated if required

Issue Reference this PR resolves

#10042

Description of Changes Made (if issue reference is not provided)

Adds support for a query-time offset parameter on timeDimensions that allows shifting time boundaries for predefined granularities (day, week, month, etc.). This enables use cases like:

• Days running 2am-2am instead of midnight-midnight
• Weeks starting on Wednesday instead of Monday

The offset parameter:

• Only works with predefined granularities (day, week, month, etc.)
• Throws a validation error if used with custom granularities
• Uses SQL interval syntax (e.g., "2 hours", "-30 minutes", "2 days")
• Is supported in REST API and GraphQL API

Includes comprehensive unit and integration tests demonstrating the day-shifting and week-shifting use cases.

[igorlukanin]

@hank-sq Please see my comment here: https://github.com/cube-js/cube/issues/10042#issuecomment-3398996431