Backlog: Toggle cursor visual states and behavior

[imdaveho]

Problem to Solve
In most text editing use cases, there should be some visual indicator to shift from insert mode to overtype mode. Having the ability to change the look of the cursor can create that visual indication to a user. This can be changing the shape: box, I-beam, underscore or the blink frequency.

Tasks

• A. add an Action that changes the cursor shape
• B. add an Action that updates the cursor blink frequency (blink / noblink)