V14 Measured Template -> Scene Region Conversion

[aaclayton]

• Eliminate all usage of the MeasuredTemplate document.
• Refactor code that references CrucibleAction#template in favor of CrucibleAction#region
• Adopt workflow for prompted placement of a SceneRegion as part of the Action confirmation dialog.
• Add improved configuration of the created scene region to contain some information and details about the action which produced it.
• Define system rules for whether effects should be constrained by walls or not. If constrained, apply such constraints to the created SceneRegion.