Support variable clockrates in Catch difficulty calculation

Updates Catch difficulty calculation to support variable clock rates (e.g., from ModTimeRamp).
Exposes `Mods` in `DifficultyCalculator` to allow derived classes to access applied mods.
Updates `CatchDifficultyCalculator` to calculate the effective clock rate for each hit object based on its start time and applied mods.
Updates `CatchDifficultyHitObject` to store the effective `CatcherSpeedMultiplier`.
Updates `Movement` skill to use the per-object `CatcherSpeedMultiplier` instead of a constant global rate.
Removes the TODO regarding ModTimeRamp support.

Includes performance optimization to pre-filter rate mods in `CatchDifficultyCalculator` and null-safety for `Mods` property in `DifficultyCalculator`.

Co-authored-by: winnerspiros <1675249+winnerspiros@users.noreply.github.com>

Author: google-labs-jules[bot]