[Feature Request] Support adding clickable elements manually

[shiqimei]

Sometimes, the vimium cannot find all clickable elements that we want to focus. It's a good idea to allow users add css rules to include extra clickable elements.

[gdh1995]

This is just like #3049 . In my memory I've saw some issues about this feature in recent years, though now I only found one, so this feature seems not interesting enough to be implemented.

[meucaa]

I'm super interested in this feature ℹ️ Many websites I'm using have non-recognized elements (important ones) 😞

[benwoodward]

This seems like an obvious feature to add, given that so many websites nowadays use onClick handlers on elements rather than anchor tags or buttons. Vimium is just not usable on a lot of websites due to this omission.

Example, I'd like to click on bidirectional links in RoamResearch using Vimium, but the clickable element is:

<span data-link-title="linked text" data-link-uid="DLX3388dd"></span>

It'd be great to be able to add [data-link-uid=*] to a list of elements to focus.