[ty] Resolve enum names for all '|' arms for literal enum subsets (#25379)
## Summary
Fixes https://github.com/astral-sh/ty/issues/3531
Currently, only a single enum value is retrieved when evaluating a match
statement against a literal of enum values. This recursively resolves a
full `|` union statement to get all the values.
## Test Plan
<!-- How was it tested? -->
- Unit tests
- Built ty and checked against repro in linked issue
---------
Co-authored-by: Charlie Marsh <charlie.r.marsh@gmail.com>