vcl: move legacy accessibility functions to own file

Change-Id: I32e10555d496ef3c9d5fa895c649e3eceb3fc366

vcl/Library_vcl.mk

@@ -104,8 +104,9 @@ $(eval $(call gb_Library_add_exception_objects,vcl,\
     vcl/source/window/abstdlg \
     vcl/source/window/accel \
     vcl/source/window/accmgr \
-    vcl/source/window/accessibility \
     vcl/source/window/brdwin \
+    vcl/source/window/accessibility \
+    vcl/source/window/legacyaccessibility \
     vcl/source/window/btndlg \
     vcl/source/window/builder \
     vcl/source/window/cmdevt \