wxGUI/datacatalog: fix setting output vector/raster format

[tmszi]

To Reproduce
Steps to reproduce the behavior:

1. Launch wxGUI
2. On the Data tab (page) choose from toolbar 'Select another import option' tool and invoke menu and choose 'Link external data' -> 'Set raster output format [r.external.out]'
3. Choose Directory as Output type
4. Choose e.g. GeoTIFF format
5. Set Directory path e.g. /tmp
6. Hit Ok button
7. You get error message

Error message

Additional info

1. 'Set raster output format [r.external.out]' dialog internally use v.external.out command instead of r.external.out and params args are incorrect
2. Mapping output formats between dialog wx.Choice widget items (which use long format name) and command r.external.out or v.external.out (which use format abbreaviation) is incorrect . Simple e.g. 'Set raster output format [r.external.out]' dialog wx.Choice format type widget use for GeoTIFF format string 'GeoTIFF', but internall command r.external.out as format param argument accept for GeoTIFF format string arg 'GTiff' (check all format options r.external.out), the same is true for 'Set vector output format [v.external.out]' dialog.

[petrasovaa]

Thanks, looks good to me, I recommend giving it little bit of time before backport, just to make sure it doesn't impact things outside of r/v.external.out.

[landam]

Not easy to backport (conflicts). @petrasovaa What about removing backported_needed label.