Plumb forced colors state to NativeTheme paint methods

This CL plumbs the forced colors state that exists as a web setting to
NativeThemeFluent's PaintScrollbarTrack() and PaintButton() methods.
Currently, these methods rely on the global NativeTheme web instance
forced colors state for handling specific painting operations. However,
this approach poses a challenge because the forced colors state within
Blink has evolved beyond the global NativeTheme web instance — it also
considers the page colors block list. Consequently, forced colors has
been implemented as a web setting within Blink(see CL:5324688).
Additionally, given that forced colors can be triggered directly in
Blink via the DevTools emulation feature, there is a need to make
these paint methods aware of this state.

To address this, we pass the forced colors state to these methods.

This change can be summarized into the following two tasks:
1.) Pass the forced colors web setting to WebThemeEngine::Paint methods
2.) Further propagation to NativeThemeFluent's PaintScrollbarTrack()
and PaintButton() methods

Bug: 1231644, 41489514
Change-Id: Id52c7b4179318380f9663b076126ccba6e64266e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5375871
Reviewed-by: Thomas Lukaszewicz <tluk@chromium.org>
Reviewed-by: Alison Maher <almaher@microsoft.com>
Commit-Queue: Sam Davis Omekara <samomekarajr@microsoft.com>
Reviewed-by: Dana Fried <dfried@chromium.org>
Reviewed-by: danakj <danakj@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1275224}