`bevy_picking`: use OS multi-click interval

## What problem does this solve or what need does it fill?

Uses the OS multi-click interval for click counting behavior, instead of a duration.

## What solution would you like?

PR #24264 adds a `multi_click_interval` field to `PickingSettings`, making the timing configurable. This should still be present, but also with an option to use the OS value instead (if available).

There's no standardized way to get the OS click interval, so there would need to be different implementations for each platform. The intial PR doesn't need to support everything.

Start by reading PR #24264 and the bevy_picking implementation around PickingSettings and multi-click timing. Identify how the configurable multi_click_interval is used, then check the platform APIs needed for an OS-provided interval. Done means retaining the existing duration option while adding an OS-value option for an initial set of supported platforms.

Written by the indexing model from the issue text.