Rename DrawCommandSpan to CanvasEffectSpan and remove UpdateAppearance (#56705)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/56705

Changelog: [Internal]

Renames `DrawCommandSpan` to `CanvasEffectSpan` for consistency with the new
`AnimatedEffectSpan`, and removes the `UpdateAppearance` interface.

`UpdateAppearance` is a marker interface that tells Android's text layout system
the span affects text appearance (triggering re-measurement). Since
`CanvasEffectSpan` only draws on top of text during `PreparedLayoutTextView`'s
draw pass and never modifies paint state or text measurement, implementing
`UpdateAppearance` was incorrect — the same reasoning applied when designing
`AnimatedEffectSpan` without it.

Reviewed By: mdvacca

Differential Revision: D97399655

fbshipit-source-id: 3865b4143d696d519abdff9a6471dbe3a9867d6f