Added fidcsi and fidall options for GE SVS - for special case of pulse-acquire scans

[DC-3T]

Added an extra function to allow GE p-files with 'fidcsi' and 'fidall' psds to be processed as SVS scans - in the special case of pulse-acquire data. Previously, the code would treat these pulse-acquire data as SVS data (no phase encoding, spatial dims = [1, 1, 1]) but the corresponding psd names were not included in the list of SVS psd's.

[wtclarke]

Hi @DC-3T , Thank you for the pull request. My understanding is that the fidall sequence can be literally anything (completely arbitrary mag-prep and readout), which is cool from a development point-of-view, but a nightmare for handling the data. Is there a way of reliably identifying this case where it is pulse-acquire, from the headers?