[12544] CMake: generic way to build a script library

Added new parameter INCLUDE_BINDINGS_DIR which can be set to the name of a
folder inside src/bindings/.

Includes the script library in src/bindings/ with the defined name.
The name must correspond to the name of the folder and the folder must contain
a valid CMakeLists.txt

Note: if you currently use a script library, you will probably get a merge
problem on src/bindings/CMakeLists.txt as you will have modified this file
manually. Please use the new version of this file and rerun CMake once with the
parameter -DINCLUDE_BINDINGS_DIR=ScriptDev2 (if you are not using SD2 but
another script library, replace ScriptDev2 with the name of the folder in
src/bindings/).

If you do not use a script library you should not have any merge problems
and you don't need to do anything.