[DOM] Treat omitted Fragment Event listener options same as `capture: false` (#37251)

`FragmentInstance` tracks its event listeners so they can be applied to
children added later, and matches them by a normalized options identity.
Omitted options currently normalize to a different identity than an
explicit `false` or `{capture: false}`, even though both mean `capture:
false` per the `EventTarget` contract, where listener identity is the
tuple of type, callback, and capture flag. As a result, a listener added
without an options argument cannot be removed with an explicit
capture-false value (or the reverse).

This change normalizes omitted options to the same capture-false
identity as `false` and `{capture: false}`. The first commit adds a test
to the FragmentRef suite characterizing the current behavior; the second
commit contains the fix and the updated assertions.

---------

Co-authored-by: Claude Code (kimi-k3[1m]) <noreply@anthropic.com>