UI: avoid term 'Region', use 'Edges & Faces' instead

Change to recent renaming of "Edge Collapse" as it has multiple uses,
as it collapses edge-rings, but isn't limited to collapsing single edges,
it can be used to collapse faces with arbitrary topology.

The name "Collapse Regions" is too vague, users might not think to use
this to collapse edge-rings.

Use a more verbose name "Collapse Edges & Faces", referencing edge-rings
in the tool-tip.

source/blender/editors/mesh/editmesh_tools.c

@@ -731,9 +731,10 @@ static int edbm_collapse_edge_exec(bContext *C, wmOperator *op)
 void MESH_OT_edge_collapse(wmOperatorType *ot)
 {
   /* identifiers */
-  ot->name = "Collapse Regions";
+  ot->name = "Collapse Edges & Faces";
   ot->description =
-      "Collapse isolated edges & faces regions, merging data such as UV's and vertex colors";
+      "Collapse isolated edges & faces regions, merging data such as UV's and vertex colors. "
+      "This can collapse edge-rings as well as regions of connected faces into vertices";
   ot->idname = "MESH_OT_edge_collapse";
 
   /* api callbacks */