feat: support contextual tools and auto-populating toolbox

 - Add a bunch of interfaces to support active editor contexts and toolsets associated with them.  This is intended to allow a contextual set of tools to be used for a given creative action.
 - Implement LayerEditContext to start that has tools related to editing the tile data of a given tilemap layer.
 - Refactor existing paint/flood/erase/move tools into IEditorTool classes.
 - Rename ActionsService to ActionManager class to better represent what it does.
 - Update gruntfile and tests to fix breaking changes.
docs(tileEditorInput): cleanup incorrect directive doc