Add tests for <timer-pause-button>.

[Works towards #46349031, closes tests task]
<timer-pause-button> tests are green.

Also added <timer-pause-button> to home page.

[Works towards #46349031, closes passing tests task.]
Add <timer-resume-button> with green tests.

Also add timer/resume functionality to MainCtrl

[Finishes #46349031, completes <timer-resume-button> task]