[Cocoa] Vertical range slider fill overshoots its value when ticks are present and the thumb is hidden

https://bugs.webkit.org/show_bug.cgi?id=326240
rdar://189116567

Reviewed by Aditya Keerthi.

When a range slider has datalist ticks and its thumb is not visible,
RenderThemeCocoa::paintSliderTrackForVectorBasedControls() extends the
fill by additionalLength (1.5 times the tick length) so that the fill
fully covers the tick for the current value.

The horizontal branch does this correctly. The vertical branch multiplied
by tickLength a second time. As a result, the overshoot was
1.5 * tickLength^2 instead of 1.5 * tickLength, and it grew with the
square of the zoom. At zoom: 3 on macOS, the fill ran 54px past the value
instead of 9px.

Use additionalLength in the vertical branch too, matching the horizontal
branch.

Test: fast/forms/form-control-refresh/range-vertical-hidden-thumb-ticks-fill-length.html

* LayoutTests/fast/forms/form-control-refresh/range-vertical-hidden-thumb-ticks-fill-length-expected.html: Added.
* LayoutTests/fast/forms/form-control-refresh/range-vertical-hidden-thumb-ticks-fill-length.html: Added.
* Source/WebCore/rendering/cocoa/RenderThemeCocoa.mm:
(WebCore::RenderThemeCocoa::paintSliderTrackForVectorBasedControls):

Canonical link: https://commits.webkit.org/322780@main