Receive: Fix fiat conversion

[kaloudis]

Description

Fiat conversion rate was broken on the receive view, when viewing sats amount when user is entering in fiat. Also added a rates display.

This pull request is categorized as a:

• New feature
• Bug fix
• Code refactor
• Configuration change
• Locales update
• Other

Checklist

• I’ve run npm run tsc and make sure my code didn’t produce errors
• I’ve run npm run prettier and formatted my code correctly

Testing

If you added new functionality or fixed a bug, did you add new unit tests?

• No, I’m a fool
• Yes
• N/A

I have tested this PR on the following platforms (please specify OS version and phone model/VM):

• Android
• iOS

I have tested this PR with the following types of nodes (please specify node version and API version where appropriate):

• LND
• c-lightning-REST
• spark
• Eclair
• LndHub

Locales

• I’ve added new locale text that requires translations
• I’m aware that new translations should be made on the Zeus Transfix page and not directly to this repo

Third Party Dependencies and Packages

• Contributors will need to run npm install after this PR is merged in
• 3rd party dependencies have been modified:
  • verify that package.json and package-lock.json have been properly updated
  • verify that dependencies are installed for both iOS and Android platforms

Other:

• Changes were made that require an update to the README
• Changes were made that require an update to onboarding