Improvements to raw input dialogue

[lauramurgatroyd]

• Show raw input dialogue for both reference and correlate images

Currently DVC code only allows the 2 raw images with same dimensions and other settings input, but it may later allow for different settings on each so we need to ask the user for details of both the ref and correlate images -> Make the second dialogue auto fill with the settings from the first dialogue. 90% of the time all of the details will be the same for ref and corr image though so this isn’t a big issue

• Save contents of raw input dialogue when saving session
  Currently when reloading a session, user has to re-enter this info

• Add preview of image slice to raw input dialogue

[paskino]

Possibly the raw image loader dialog should go in the viewer.

[lauramurgatroyd]

currently it lives in the io.py file in the viewer

https://github.com/vais-ral/CILViewer/blob/0f40703e1ae689ac806bced64eb2e05e7f20bd67/Wrappers/Python/ccpi/viewer/utils/io.py#L514

[paskino]

maybe not any longer as we removed that file.

[DanicaSTFC]

The raw input dialog has been implemented in TomographicImaging/CILViewer#356 and TomographicImaging/CILViewer#410