COMP: Simplify how arguments are passed to PackageAndUploadExtensions script

Parameter are now written into files like:
<extension-name>-test-command-args.cmake
<extension-name>-upload-command-args.cmake
<extension-name>-upload-only-command-args.cmake

This file are then passed to the ctest using argument:

-DSCRIPT_ARGS_FILE:FILEPATH=<path-to-args-file>

and include within the ctest script using:

include(${SCRIPT_ARGS_FILE})

This approach has the advantages of:
1) being simpler in the sens it avoids escaping arguments
2) preventing issue related to the command line length on windows by passing
arguments "through a file"

See 0002491 - http://www.na-mic.org/Bug/view.php?id=2491

git-svn-id: http://svn.slicer.org/Slicer4/trunk@21682 3bd1e089-480b-0410-8dfb-8563597acbee