fix(transfer): flag processing not perfect

[hjpalpha]

Summary

• shut up an anno warning in transfer display
• switch from countrycode to countryname for storage/processing
  • can't use alpha2 country code due to it not supporting the shitty uk sub flag stuff
  • can't use alpha3 country code due to it not supporting:

--   ISO 3166-1 alpha-2 User-assigned Code Elements
['xk'] = 'kosovo',
['xx'] = 'nonrepresenting',

alternative solution would be to add user assigned alpha3 country codes for those 2 cases... (xkx for Kosovo and xxx for non rep)
lmk if that is prefered

How did you test this change?

untested on wki, don't have the time atm
golden/smoke tests should be enough