Integrate MNS service to support domains as address and public keys providers

[masquel]

1. Support resolving domain and checking response signature in CoinSendForm
2. Support resolving domain and checking response signature in ValidatorDelegateForm
3. Support resolving domain and checking response signature in ValidatorUnbondForm
4. Support resolving domain and checking response signature in ValidatorReinvestForm
5. Add Loader component
6. Add loading state in FieldQr

[shrpne]

Thank you!