[FEAT] Better feedback returned when transaction is posted to propagation node

[icellan]

Is your feature request related to a problem? Please describe

A user would be greatly helped with better feedback from Teranode when a Transaction is posted to the propagation service. For instance, whether the transaction was queued, processed or added to a block template, also whether it was added, or added previously.

Describe the solution you'd like

Add status fields to the response from the /tx and /txs propagation endpoints about the transaction(s) just posted.

Describe alternatives you've considered

Additional context

Return values should include:

• status (queued, processed, added, added-earlier)
• blockHeight (if added earlier and mined into a block)

[sirdeggen]

Discussion: 204 for Queued, 200 or 201 for "we actually did the utxo lookup and it's a valid spend".