* first pass of adding grid snapping button
* update to request current grid size
* show/hide snapping option based on selection
* small tidy-up changes
* small updates following review feedback
* added some unit tests for snapping functionality and some small tidy-up/refactoring
* small refactor to ensure snap to grid ui only appears with snapping enabled
* add missing include to resolve build error
* fixes for build
* add & to make compiler happy
* formatting changes to AzToolsFramework viewport related types + API comment style updates
* minor format change - include ordering
* improve formatting by moving comment
* fix compile error and switch to use AZ_Printf
* small polish changes after review feedback
* Clarify ViewportWorldToScreen being in widget space and add DeviceScalingFactor
* -Fix viewport icons being draw wrong on high DPI displays
-Fix loading viewport icons from absolute paths, which
* Address review feedback, fix build
Tom Hulton-Harrop
Nicholas Van Sickle
hultonha
alexpete