Bitcoin Core GUI getrawtransaction implementation

[zndtoshi]

Bitcoin Core offers sovereignty by people controlling their keys and validating those keys. But many users today hold their keys on hardware wallets or mobile wallets and it's a bit difficult to connect those wallets to a full node and validate them.

The cli users have the option to "getrawtransaction txid true" in order to find valuable information about a transaction that could be theirs. This is a very powerful api call that effectively eliminates the need of an Electrum server.

I think many users would find a lot of value in easily verifying their personal transaction directly from Bitcoin Core GUI!

Something like Help -> Verify external txid. There would need to be an option to enable txindex also. This would greatly increase the use of Bitcoin Core for the ease of validating a transaction. Sure users could create a watch only wallet but these are extra steps that maybe many of the non technical users would get discouraged from doing.

[promag]

GUI users can use the RPC console. Anyway, Concept ACK

[fanquake]

Moved to bitcoin-core/gui#645.