show sstxcommitments on address page

[raedah]

here is an example address https://explorer.dcrdata.org/explorer/address/DskgNAYth1WRxYLzY6VUjeYPANwTbnNRKgk this is the corresponding vote tx https://explorer.dcrdata.org/explorer/tx/715b1668a006c067ee56de5d2356e66dbe530dda8b12849424d2559001f21fac this is the ticket with the sstxcommitment https://explorer.dcrdata.org/explorer/tx/06342b4ba77202397f6412be8eda76d62939c08fd84fd9ca2be86a69a037850e

Along with this, we can add a Type column to the list of transactions.

[raedah]

This should now be working in lite mode, but not in full mode.

[chappjc]

Also note that the logic on the address page for determining the transaction output type is incorrect:

https://github.com/decred/dcrdata/blob/a3c621fd98056284c8d38d261c269e61c6fb05d1/views/address.tmpl#L152-L157

sstxcommitment isn't the only zero value output of interest, there is sstxchange too.

Instead of doing all this (and incorrectly) in the template, a go type can be given a method to return the actual type.

[raedah]

related to https://github.com/decred/dcrdata/issues/377