Get rid of unused wxTransformMatrix

As it is stated in matrix.cpp wxTransformMatrix was intended to be used
in wxDC to replace the basic system of scaling/translation but actually
it was never used.
Because applying affine transformations can be done with wxAffineMatrix2D
and wxDC::SetTransformMatrix() we can get rid of this dead code.

Closes #13114.

build/bakefiles/files.bkl

@@ -883,7 +883,6 @@ IMPORTANT: please read docs/tech/tn0016.txt before modifying this file!
     src/common/lboxcmn.cpp
     src/common/listctrlcmn.cpp
     src/common/markupparser.cpp
-    src/common/matrix.cpp
     src/common/menucmn.cpp
     src/common/modalhook.cpp
     src/common/mousemanager.cpp
@@ -1188,7 +1187,6 @@ IMPORTANT: please read docs/tech/tn0016.txt before modifying this file!
     wx/listbase.h
     wx/listbook.h
     wx/listctrl.h
-    wx/matrix.h
     wx/menuitem.h
     wx/metafile.h
     wx/minifram.h