Open Channel: use AmountInput to display fundMax

[myxmaster]

Description

This displays the local amount in AmountInput if Use all possible funds is enabled, making it consistent/less flickering to normal view.

I added forceUnit prop to AmountInput to force it to sats mode, which is obviously needed when Use all possible funds is used.

When you disable it again, values get reset properly.

Before	Before	After

This pull request is categorized as a:

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

Checklist

• I’ve run yarn run tsc and made sure my code compiles correctly
• I’ve run yarn run lint and made sure my code didn’t contain any problematic patterns
• I’ve run yarn run prettier and made sure my code is formatted correctly
• I’ve run yarn run test and made sure all of the tests pass

Testing

If you modified or added a utility file, 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):

• Embedded LND
• LND (REST)
• LND (Lightning Node Connect)
• Core Lightning (CLNRest)
• LndHub
• [DEPRECATED] Core Lightning (c-lightning-REST)
• [DEPRECATED] Core Lightning (Spark)
• [DEPRECATED] Eclair

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 yarn after this PR is merged in
• 3rd party dependencies have been modified:
  • verify that package.json and yarn.lock 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

[kaloudis]

Why do we have to change the unit to sats when it's toggled?

[myxmaster]

I think it would be misleading if we had a fiat amount in the amount input, even when it is correctly calculated and the sat amount below in small.
So only ₿ or sats would be good to use, and then I think sats is better.

[myxmaster]

(rebased)