fix: transaction sending logic & UI issues

[shahin-hq]

Summary

Depends on: #962

Closes: https://app.clickup.com/t/86dvzm6fu

This PR fixes various issues with transaction sending.

• uses active network from navbar for validator registration/resignation
• fixes disabled continue button for validator resignation when page loaded with no wallets
• various UI improvements

Checklist

• My changes look good in both light AND dark mode
• The change is not hardcoded to a single network, but has multi-asset in mind
• I checked my changes for obvious issues, debug statements and commented code
• Documentation (if necessary)
• Tests (if necessary)
• Ready to be merged