Add precise transform tools

[joelspadin]

Currently there are keyboard shortcuts for rotating objects by 90 degrees, but it is not possible to control the center point of the rotation. There are fights that take a pattern of AOEs and repeatedly rotate them by values that aren't 90 degrees, so being able to rotate a group of objects by smaller increments would be useful.

While I'm at it, I should implement the full set of transformation tools:

• Rotate objects by specific angle, around center of selection or specific X, Y center point
• Move selected objects by specific X, Y values
• Scale selected objects by specific X, Y values, around center of selection or specific X, Y center point
  • This may be difficult to implement when some objects are rotated or do not support being resized independently on X and Y. Maybe instead of X, Y scale, just support proportional scale?

Align and distribute tools could be useful as well, but not as high priority. Possible options include:

• Move/align as a group or each object individually?
• Move/align relative to arena/selection
• Center vertically/horizontally
• Align left/right/top/bottom edges
• Distribute horizontally/vertically with even spacing between centers, left/right/top/bottom edges, or even horizontal/vertical gaps

Where should these tools go? Some possible options include:

• Add a third panel.
  • On small screens, have a single panel with three tabs.
  • On medium size screens, use tabs for properties + new panel, and have scene panel separate.
  • On large screens, show all three panels.
• Have toolbar buttons and/or keyboard shortcuts that open a floating window with the tool controls