Coinbase transactions during chain reorganizations perpetually pending

[braydonf]

Versions
bcoin v1.0.2

Expected

Either the mining coinbase transaction is shown as unconfirmed in a wallet after a reorganization or be removed. The prior is currently the case.

Actual

Coinbase transactions will perpetually become unconfirmed during a chain reorganization with a competing chain. These transactions will then be attempted to be broadcast to peers upon a rebroadcast attempt (this has been fixed in #605).

Reproduce

There is a test case in #605 that generates reorgs and coinbase transactions are unconfirmed.

Workaround

Use abandontransaction to remove the transaction that will never be confirmed.