Merge account_fund and account_send, support sending of all wallet data

The Issue

This came up on a call with @eukreign and @akinwale today when we discussed being able to easily transfer content from one account to another for cross device sync purposes. It would be useful for transferring to/from web accounts if we decide to go that route as well, and also for anyone who wants to easily move all their data from one wallet to another.

If we can get this done soon, would be really useful to support YT content transfers instead of manually sending claims + channels + tips: https://github.com/lbryio/internal-apis/issues/761

Overall goal: account fund and send would be combined so that one could spend all funds from a single account into a wallet address. If it makes more sense to keep these separate, that can still happen, but account fund/send would need to support sending of all claims, balances, channels (what about certificates?), and supports (to appropriate claims).

System Configuration

• LBRY Daemon version:
• LBRY App version:
• LBRY Installation ID:
• Operating system:

Anything Else

Screenshots

Internal Use

Acceptance Criteria

Definition of Done

• Tested against acceptance criteria
• Tested against the assumptions of user story
• The project builds without errors
• Unit tests are written and passing
• Tests on devices/browsers listed in the issue have passed
• QA performed & issues resolved
• Refactoring completed
• Any configuration or build changes documented
• Documentation updated
• Peer Code Review performed

No files or tests are named. Start by locating the account_fund and account_send entry points, then trace how accounts handle claims, balances, channels, certificates, and supports. Done means an agreed design and passing tests for transferring all specified wallet data into a destination address.