#14411 Enforce name uniqueness for surfaces, polygons and folders

[magnesj]

Closes #14411

Names must be unique among siblings sharing the same parent folder. Items in different folders may keep identical names, and comparison is case sensitive.

Approach

Both trees now sit on caf::PdmNestedCollection<SelfT, ItemT>, which keeps items in m_items and folders in m_subCollections. RiaNameUniquenessTools builds on that: siblings are simply the other objects in the same caf::PdmChildArrayField, reached through parentField(). That makes one generic helper enough for surfaces, polygons and folders, and it gives two properties for free — folders and items are separate namespaces, and names in different folders never collide.

Rename

Hooked in fieldChangedByUi on RimSurface, RimPolygon, RimSurfaceCollection and RimPolygonContainer, the last covering polygon folders and RimPolygonFile. Tree-view and property-editor renames both funnel through there, and it is the only place with the old value available for the cancel path.

On a collision RiuNameConflictTools::resolveRenameConflict offers the auto-generated name:

"Top" already exists in this folder. Use "Top_1" instead?    [ Use "Top_1" ] [ Cancel ]

Cancel restores the previous name. When no GUI is running, the unique name is applied without prompting, so console mode, regression tests and gRPC-driven field writes never block on a modal dialog.

Auto-rename

Applied where no user is present to decide: manual creation, Add Folder, surface and polygon file import, polygons generated from one file, create-copy, duplicate, and drag and drop between folders. Drag and drop needed no change in RiuDragDrop, as it routes through addSurfacesAtIndex.

Python API

RiaDefines::NameConflictPolicy with FAIL (default), AUTO_RENAME and OVERWRITE, exposed as on_name_conflict on AddFolder, CreatePolygon, ImportSurface and NewRegularSurface:

root.create_polygon(name="Fence", coordinates=coords)                       # raises on collision
root.create_polygon(name="Fence", coordinates=coords,
                    on_name_conflict=rips.NameConflictPolicy.AUTO_RENAME)   # -> Fence_1

NewSurface is deliberately left out. Grid case surfaces derive their tree label from the case and K index and carry no name of their own, so a flag there would never fire.

Notes

Objects with an empty name are exempt from numbering, for the same reason — otherwise six grid case surfaces would render as _1 - K:3.

Existing projects are not migrated. Project load deserializes straight into the child arrays, so duplicates already stored in a project file survive and are resolved as the user touches them. All in-project references to surfaces and polygons are PdmPtrField, so adding a migration pass later stays safe.

caf::PdmNestedCollectionBase::subCollectionsField() is added so the generic AddFolder can inspect sibling folders without knowing the concrete collection type.

Verification

Full build clean. 960/960 C++ unit tests pass, including 7 new ones for the suffix rule, case sensitivity, per-folder scoping, separate namespaces and the conflict policy. 10/10 rips tests pass, including 3 new ones covering the Python flag across all three modes.