feat: Add support for `$click()`ing {bslib}'s input task button #828

Job	Run time
website / pkgdown	5m 3s
routine / routine	4m 58s
R-CMD-check / setup	6s
R-CMD-check / macOS-latest (4.4.1)	3m 27s
R-CMD-check / windows-latest (devel)	6h 4m 57s
R-CMD-check / windows-latest (4.4.1)	37m 45s
R-CMD-check / windows-latest (4.2)	40m 47s
R-CMD-check / windows-latest (4.1)	37m 32s
R-CMD-check / windows-latest (3.6)	2h 52m 47s
R-CMD-check / ubuntu-20.04 (devel)	20m 42s
R-CMD-check / ubuntu-20.04 (4.4.1)	6m 15s
R-CMD-check / ubuntu-20.04 (4.3.3)	6m 7s
R-CMD-check / ubuntu-20.04 (4.2.3)	5m 58s
R-CMD-check / ubuntu-20.04 (4.1.3)	6m 16s
R-CMD-check / ubuntu-20.04 (4.0.5)	5m 31s
	11h 58m 11s

Provide feedback