DialogService: three butons and a checkbox

[isidorn]

Currently the dialogService only allows me to have a checkbox if I do a confirm. Due to that I can only have two buttons and a checkbox.
It is not possible to have multiple buttons and a checkbox. I would expect this to be possible if the confirm would accept multiple buttons, or if the show would support the checkbox.

fyi @bpasero

[bpasero]

Caution though, the show signature currently does not give any indication if the checkbox was clicked by the user or not, so it would need to provide this info.

[isidorn]

@bpasero agree fully. We would need to change the return value

Also fyi I need this for #68084
@sbatten If you do not have time to add this, let me know if you are ok with me adding this APi to the dialogService.

[sbatten]

I'm okay with this change. As for being careful, when updating references, the progress service will need special attention to make sure we don't break reconnection

[isidorn]

@sbatten what do you prefer that I do:

1. change the confirm API to allow multiple buttons
2. change the show to allow checkboxes and to return a richer result?

[sbatten]

@isidorn my opinion is that show is intended for a more complete experience and confirm is for fairly boolean response. I think that show can be expanded to fit that.

[isidorn]

Will be verified as part of #68084, thus adding verified label.