Check widget: Only respond to hover and tap over the checkbox or label

[dweymouth]

Description:

Fixes #4527, related to #4320

Updates the Check widget to only respond to hover and tap events over either the checkbox or the label area of the widget. If the widget is wider or taller because it is placed in a container that maximizes its size, ignore events outside the "active" area of the widget.

The first commit of this PR just reordered the functions in check.go in a way that made more sense (resulting in an inflated line count diff relative to the actual code change). To review, you may wish to only look at the second commit.

Note: the behavior can be tested with fyne_demo. Before this change the check widget could be toggled by tapping far to the right, well beyond the end of the label. With the behavior, tapping/hovering in that area of the widget (which intuitively to the user is not part of the widget at all) does nothing

Checklist:

• Tests included.
• Lint and formatter run with no errors.
• Tests all pass.

[coveralls]

coverage: 64.684% (+0.1%) from 64.55%
when pulling c630423 on dweymouth:check-tappable-area
into 8458aff on fyne-io:develop.

[Jacalz]

Did you mean to request a review? :)

[dweymouth]

Yes, this pr is ready for review :)

[Jacalz]

I mean given that you assigned me and Andrew to it? ;)

[dweymouth]

Just wasn't sure how you had notifications setup

[Jacalz]

Alright, cool. Absolutely no problem. Just though you might have wanted us to do something else than review :)

[Jacalz]

Thanks. Really nice change. More consistency with the Radio widget 👍
Just left one minor suggestion inline

[Jacalz]

Wonderful work. Thanks :)