Spike for 'context sensitive actions'

[TheGrayStone]

closes #208

This is based on the reworked menu item structure

[niklasmohrin]

Neat, this works with only this small change 👍

There are some things that I noticed though (mostly no must-haves for this spike):

• the keyboard focus is reset to the end of the input field after a second or so, so moving to the beginning of the input is virtually impossible. We've got to come up with something better than just moveCursorToEnd (same goes for say selecting some text)
• the above problem also means that the text is unselected very quickly when you open algernon, so you usually start appending to your last query instead of overwriting it
• when activating algernon while hovering over an entry of a right-click-menu, the menu disappears, but algernon doesn't get keyboard focus, so neither querying nor closing with esc work. one can click into the input field to fix that glitch
• I think we want to have separate icons for these actions. Otherwise, lots of results have the world icon. in my opinion, having these results as their own type seems appropriate in any case
• do we know that all of the context menus consist of MenuMorphs?
• results from the second page (after you click "more") are not included, for example "inspect subinstances". with the current approach, I don't really see us finding these any time soon though (and it isn't really a must, not even for the first release of this feature imo)
• talking about the approach: while it is very direct and effective, I wonder if we could only "fetch" the results from the normal provider that is used by the browser (<= really assuming some architecture of the system browser right here). "clicking around" in the world on every keypress doesn't sound very safe. Are there any scenarios where right-clicking actually really does something meaningful (more than the example above)? That would be pretty bad