Allow optional signing in createTX http endpoint

[nodech]

HTTP Endpoint for creating transaction is also signing the transaction.
We have another endpoint /sign which can be used for signing.

• Makes tx sign optional /wallet/:id/create (true by default for backwards compatibility)

[christsim]

This will also allow for creating unsigned transactions from watchOnly wallets.

[tuxcanfly]

Instead of this breaking change, why not add another end point?

[christsim]

Another endpoint is fine by me, although another solution would be to not attempt to sign the transaction if it is a watchOnly wallet - instead just return the unsigned transaction.

[nodech]

We could also add sign parameter. We can set it true by default and it won't be breaking change.

[tuxcanfly]

Yup, that sounds good.

[tuxcanfly]

While we're here, we should accomodate the offline signing use case, for which we need derivation paths for inputs: see #485

We can add support for this by simply returning wallet.toDetails(tx) instead of just tx.

[tuxcanfly]

      const details = await req.wallet.toDetails(tx);

      res.json(200, details.toJSON(this.network, this.wdb.height));

[tuxcanfly]

Since most of the time when we create a raw transaction, we also need the input paths for offline signing, I propose we leave this call as it is and create a new endpoint (maybe /raw?) and use it to create raw transactions, with the output consisting of wallet.toDetails(tx). Thoughts?

[joemphilips]

What about /txtemplate ? sounds more verbose.

[nodech]

@tuxcanfly That would make sense, but that belongs to new Pull request that can update all the API methods with necessary changes. Probably create an issue and move discussion there.

I will keep this simple and just update sign to be true by default and avoid making it breaking change (Can be released as minor update, even without changelog mention).

[BluSyn]

Can we get this merged? Feature is highly desired.

[tuxcanfly]

Looks good. Let's create a new issue to follow up on offline signing.