Tool shortcuts for marker: Reset/increase/decrease counter

[RobertMueller2]

Description

This may be useful as a stand alone feature, but even more so if/when components are added with #159.

[RobertMueller2]

I'm thinking tool specific actions could also be shown in a popover for better indication that there are some available, but

• This may compete with UI for feature: Tool secondary, tertiary modes #538
• if it is visible by default during editing mode, it may cover parts of the image and get in the way