feat: English ITN enhancements from NeMo reference

[pengzhendong]

Summary

Backport features from NeMo's English ITN that were supported in code but not covered by their test suite.

Time

• Numeric minutes with "past" (e.g. "ten past four" → 04:10)
• "till" alias for "to" (e.g. "quarter till two" → 01:45)
• "o' clock" / "o clock" variants
• Zero-pad hours in to_hour.tsv

Telephone

• "triple X" → XXX (e.g. "triple five" → 555)

Date

• BCE, CE and long-form suffixes ("before common era", "common era")
• H1/H2 financial half-year periods
• Century ranges ("nineteen hundreds" → 1900s)
• Millennium ranges ("two thousands" → 2000s)
• "X hundred" year form ("nineteen hundred" → 1900)

Measure

• Replace cdrewrite on VSIGMA with finite string_map for pluralization — fixes OOM on runtime compose
• Proper -ies/-es rules and irregular plurals (feet, inches, ounces)
• Fix "per" unit weight to prefer direct TSV matches (e.g. mph over mi/h)

Test plan

• 487 project unit tests pass (3.04s)
• NeMo test suite: 469/470 (99.8%), no regressions
• All normalize calls < 3ms