[Gimp-gui] Layer mask button for the layers toolbar, feature additions?

[Ben <draekko software gmail com>]

I had posted a patch to a bug report to add support for a button to be 
added to the toolbar for the layer dialog/widget (see 
https://imgur.com/wkyxoqM), but it's been suggested i post here for 
starters to start a dialog. So here i go :)

I was wondering what the reticence to having the button there was. 
Photoshop has a similar feature to add layer masks which avoids having 
to reach for the menu to enable it.

It was originally suggested i just make a keyboard shortcut but for me 
and i would think for a lot of people that would not be exactly 
feasible. I already have too many apps that could make use of that and 
too few keys on the keyboard i could de-allocate from them as-is :)

For me and most folks coming from photoshop who may give GIMP a try 
would find this slowing us down considerably in our work flow 
(especially when working on composites where masking is heavily used).

Hence why i came up with a patch to add a button to add them from the 
interface and opened a bug report for that.

Having said that, i've spent the week since pondering an alternative 
that could solve everyones dilemma, which would be to add the ability to 
ctrl-click the selected layer to enable a layer mask (which if that were 
added, it would be trivial add the opposite effect to remove the layer 
mask by also ctrl-clicking).

I haven't looked at the code yet (been busy with this whole icon themes 
business lol) so not sure how feasible/work it involves but if it will 
never get added there isn't much point for me to go on and try to 
implement it.

So here we are, what do you all think?