introduce docmodel comp., model::ThemeColor, use it in SvxColorItem

Added a new component docmodel, that has the document model types,
which only depend on other basic components. This is needed so the
types can be used in every relevant component - xmloff, oox, svx,
editeng,...

Introduces model::ThemeColor, which is a class used to store the
theme color data, including transformations (svx::Transformation).
For UNO use XThemeColor is added, and the implementation UnoThemeColor
which wraps svx::ThemeColor, so it can be tranported around.

Reactor all the code and tests to accomodate for this change.

Change-Id: I7ce6752cdfaf5e4d3b8e4d90314afa469dd65cfc
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/144847
Tested-by: Jenkins
Reviewed-by: Tomaž Vajngerl <quikee@gmail.com>
diff --git a/RepositoryModule_build.mk b/RepositoryModule_build.mk
index 2f3a06e..2059c1f 100644
--- a/RepositoryModule_build.mk
+++ b/RepositoryModule_build.mk
@@ -63,6 +63,7 @@
 		configmgr \
 		connectivity \
 		cppcanvas \
+		docmodel \
 		drawinglayer \
 		editeng \
 		emfio \