Small fixes to Electrum and Esplora APIs

[thunderbiscuit]

This PR cleans up some of the method and argument names we had not mirrored correctly from the Rust side.

• full_scan_request -> request docs
• sync_request -> request docs
• (Electrum) broadcast -> transaction_broadcast docs

Changelog notice

Changed:
  - The full_scan and sync methods on the Electrum and Esplora clients now take a renamed `request` argument [#642]
  - ElectrumClient::broacast was renamed ElectrumClient::transaction_broadcast to mirror the Rust API [#642]

[#642]: https://github.com/bitcoindevkit/bdk-ffi/pull/642

All Submissions:

• I've signed all my commits
• I followed the contribution guidelines
• I ran cargo fmt and cargo clippy before committing

New Features:

• I've added tests for the new feature
• I've added docs for the new feature

[reez]

ACK 315c379

Let me know if need another ack after rebase on #641 once merged or anything

Love these kinds of PR's, shows people we are on top of things and not letting stale naming slip by for too long.

[thunderbiscuit]

Yeah it actually has your ACK but not the "approved" in the GitHub UI, so I can't merge. But also the tests appear to be blocked...

[reez]

Bah! just "approved" so should be unblocked for that part now