feat(compiler): add missing ops (xorq-labs#1441)

The missing ops are:

**Extraction Operations:**
- Date: Extract date from timestamp
- Time: Extract time from timestamp

**Current Time Operations:**
- TimestampNow: Current timestamp (use xo.now())
- DateNow: Current date (use xo.today())

**Arithmetic Operations:**
- DateAdd: Add interval to date (e.g., date + interval)
- DateSub: Subtract interval from date (e.g., date - interval)
- DateDiff: Calculate difference between two dates (returns integer)

**Delta Operations:**
- DateDelta: Extract specified part from date difference (e.g., days,
months, years)
- TimestampDelta: Extract specified part from timestamp difference
- TimeDelta: Extract specified part from time difference

Author: mesejo