Add missing transaction details data for channels

[michele-franchi]

Currently not all transactions data is returned from /v2/txs/:transactionId endpoint.

It would be useful to include the following data for these "Channel" transactions types to have a more detailed overview of these transaction types:

ChannelCreateTx:

• Sent by

ChannelCloseMutualTx:

• Responder
• Initiator

ChannelCloseSoloTx:

• Round
• Initiator
• Initiator amount
• Responder
• Responder amount

ChannelSlashTx:

• Round

ChannelSettleTx:

• Initiator
• Initiator amount

ChannelSnapshotSoloTx:

• Round
• Initiator
• Initiator amount
• Responder
• Responder amount

ChannelForceProgressTx:

• Initiator
• Initiator amount
• Responder
• Responder amount

[sborrazas]

I've now added the /v2/channels/:id page for being able to retrieve most of this information. The round number updated on every snapshot and slash transaction is still missing. It will be added by @jyeshe in the future

[jyeshe]

@michele-franchi I am closing this considering it done as the issue involving channels is for another reason. The fields that you will find missing are for the reasons:

• ChannelCreateTx: If there is no particular case missing the sender would be the initiator (after the creation, other transactions could be initiated by delegates). Actually the sender could be by someone paying_for the channel creation but it would be associated already in /txs. Fell free to open a specific issue if there is a specific requirement to make any additional relation with paying_for, ga_meta or other sender context.
• ChannelCloseSoloTx, ChannelSnapshotSoloTx and ChannelForceProgressTx: The amounts are available only at microblock that might have multiple channel transactions in a way that could lead to imprecision if we put in these transactions. It was added a parameter to /channels/:channel though to allow querying the channel state including the amounts and reserve at a specific micro block.
• ChannelSettleTx: please use initiator_amount_final