Detect ages written as spelled-out numbers

[jzonthemtn]

The age filter detects numeric ages only. Ages written as spelled-out numbers are not detected:

the patient is thirty-five years old
a thirty-five-year-old patient
she is aged forty-two
he is one hundred years old

Java added these in 4.0.0. It builds a number-word fragment covering 0 to about 119 (ones, teens, tens optionally followed by a ones word, and an optional (one|a) hundred (and)? prefix) and uses it in two patterns: the spelled-out equivalent of N years old and of age N. See AgeFilter in philterd/phileas for the reference implementation.

Acceptance Criteria

• thirty-five years old, thirty-five-year-old, aged forty-two, and one hundred years old are detected
• Hyphenated and space-separated compound numbers both work (thirty-five, forty two)
• The spelled-out form works with the age/aged keyword as well as the years old phrasing
• A phrase such as she left five years ago is not redacted as an age
• Detection is case-insensitive
• Tests cover the spelled-out forms in tests/test_age_detection.py