Add UE::ToolTarget::SupportsIncrementalMeshChanges() and ::ApplyIncrementalMeshEditChange(), these allow a Tool to directly edit a DynamicMeshComponent in the level (and emit corresponding MeshChange) so that a Tool can emit multiple undoable edits on a DynamicMesh
Add new USingleTargetWithSelectionTool base tool class, this is a USingleSelectionTool that can receive a FGeometrySelection. USingleTargetWithSelectionToolBuilder configures this type of Tool as necessary.
Add new LinearExtrusionOp dynamic mesh operator, provides linear-extrusion API to FOffsetMeshRegion using new Operator design (mesh shared via FSharedConstDynamicMesh3, CalculateResultInPlace() function to simplify direct usage in geometry script/etc)
Add new ExtrudeMeshSelectionTool, subclass of USingleTargetWithSelectionTool, exposes new LinearExtrusionOp, uses above ToolTarget functions to directly edit DynamicMeshComponent where possible
Enable new Tool in Modeling Mode
Add a few new functions to UMeshOpPreviewWithBackgroundCompute to simplify configuring InProgress and Secondary materials
Small additions to USingleSelectionTool
#preflight 639a3e250a671525500d8a7e
#rb none
[CL 23520421 by ryan schmidt in ue5-main branch]
