decred: Add ledger wallets.

[JoeGruffins]

Description

Add the ability to use the decred wallet with ledger. The flow follows litecoin the closest with a few changes.

Pull Request - Checklist

• Initial Manual Tests Passed
• Double check modified code and verify it with the feature/task requirements
• Format code
• Look for code duplication
• Clear naming for variables and methods
• Manual tests in accessibility mode (TalkBack on Android) passed

[JoeGruffins]

I hope it's alright to make this pr out of the blue. We kinda promised decred users to add this ability and since other wallets have it I didn't think it would be a problem philosophically.

Still testing and touching up comments but would appreciate any feedback. Thanks.

Are the check boxes for anyone to do or just us or just you?

[JoeGruffins]

Currently also has changes from the branch CW-1207-Enable-multiple-bip39-wallet-creation-restore since there are some decred related changes in there. Will wait to update this further when those changes are in main.

[JoeGruffins]

I thought the changes I wanted were in CW-1207-Enable-multiple-bip39-wallet-creation-restore but can't find them now...

[JoeGruffins]

It was #2594 I was looking at, not that other branch.