Core: Ensure classes match their header filename

Also drop some unused files.

Renamed:
- `core/dvector.h` -> `pool_vector.h`
- `core/io/resource_import.h` -> `resource_importer.h`
- `core/sort.h` -> `sort_array.h`
- `core/string_db.h` -> `string_name.h`

Dropped:
- `core/allocators.h`
- `core/os/shell.h`
- `core/variant_construct_string.cpp`

1 files changed, 1 insertions, 1 deletions

diff --git a/servers/physics_2d/shape_2d_sw.cpp b/servers/physics_2d/shape_2d_sw.cpp
index 558700f400..b622550ec9 100644
--- a/servers/physics_2d/shape_2d_sw.cpp
+++ b/servers/physics_2d/shape_2d_sw.cpp
@@ -31,7 +31,7 @@
 #include "shape_2d_sw.h"
 
 #include "core/math/geometry.h"
-#include "core/sort.h"
+#include "core/sort_array.h"
 
 void Shape2DSW::configure(const Rect2 &p_aabb) {
 	aabb = p_aabb;