ft_interactivelign add hidden option to skip the interactive part

although it would defy the purpose of the function, it may be useful to have an (perhaps undocumented) option to skip the interactive part of the function. This would allow for easier non-interactive testing. The current context is the preparation of the MEG-OPM toolkit, where the test_tutorial_coregistration_opm can only run for the non-interactive parts. ft_interactiverealign supports inputting already translations/rotations etc, so the alignment could in principle be done non-interactively