[Gandiva] Complete timestamp precision support for all datetime functions

[telemenar]

Summary

This PR completes the implementation of timestamp precision support for all Gandiva datetime functions, building on the infrastructure established in #128.

Changes

Phase 4: Extract Functions

• Implement extractMonth, extractDay, extractHour, extractMinute, extractSecond for all precisions
• Implement extractDoy, extractDow, extractQuarter, extractWeek for all precisions
• Implement extractEpoch, extractMillennium, extractCentury, extractDecade for all precisions

Phase 5: Date Truncation Functions

• Implement date_trunc_Second/Minute/Hour/Day/Week/Month/Quarter/Year for all precisions
• Implement date_trunc_Decade/Century/Millennium for all precisions
• Add new date_trunc_Millisecond (for us/ns) and date_trunc_Microsecond (for ns)

Phase 6: Timestamp Arithmetic Functions

• Implement timestampaddSecond/Minute/Hour/Day/Week for all precisions
• Implement timestampaddMonth/Quarter/Year for all precisions
• Support both argument orders: (int, timestamp) and (timestamp, int)

Phase 7: Cast and Conversion Functions

• Implement timestamp-to-timestamp precision casts (all 12 combinations)
• Implement castDATE for all timestamp precisions
• Implement castTIME for all timestamp precisions
• Implement datediff for all timestamp precisions

Phase 8: Remaining Functions

• Implement months_between for all timestamp precisions
• Implement last_day for all timestamp precisions

Functions Implemented

Category	Functions	Precisions
Extract	14 functions	sec, ms, us, ns
Truncate	11+ functions	sec, ms, us, ns
Arithmetic	8 functions	sec, ms, us, ns
Cast	castTIMESTAMP, castDATE, castTIME	sec, ms, us, ns
Other	datediff, months_between, last_day	sec, ms, us, ns

Testing

• Comprehensive unit tests for all functions with all precisions
• Tests for edge cases (year boundaries, negative timestamps, precision conversion)

Dependencies

• Depends on [Gandiva] Add timestamp precision support infrastructure and extractYear POC #128 for core infrastructure

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Co-authored by Augment Code

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Pull Request opened by Augment Code with guidance from the PR author