Geometry Nodes: Separate and Delete Geometry for fields

Delete Geometry:
This adds a copy of the old node in the legacy folder and updates the
node to work with fields. The invert option is removed, because it is
something that should be very easy with fields, and to be consistent
with other nodes which have a selection. There is also a dropdown to
select the domain, because the domain can't be determined from the
field input. When the domain does not belong on any of the components
an info message is displayed.

Separate Geometry:
A more general version of the old Point Separate node. The "inverted"
output is the same as using the delete geometry node.

Differential Revision: https://developer.blender.org/D12574

source/blender/blenkernel/BKE_node.h

@@ -1515,6 +1515,9 @@ int ntreeTexExecTree(struct bNodeTree *ntree,
 #define GEO_NODE_CURVE_SET_HANDLES 1100
 #define GEO_NODE_POINTS_TO_VOLUME 1101
 #define GEO_NODE_CURVE_HANDLE_TYPE_SELECTION 1102
+#define GEO_NODE_DELETE_GEOMETRY 1103
+#define GEO_NODE_SEPARATE_GEOMETRY 1104
+
 /** \} */
 
 /* -------------------------------------------------------------------- */