Value Out versus Transparent Value Out

[leto]

As I recently took over the main HUSH explorer at https://explorer.myhush.org, I realized that the main index renders t -> z (shielding) transactions as having 0 value out, which incorrect, it's actually Unknown. Instead of having conditional code to render that string, I chose to rename the column to Transparent Value Out which now makes the 0 correct, and the mathematician in me happy 😃 .

The conditional code would actually be quite complex, because it's possible to send to multiple zaddrs and taddrs in a z_sendmany, so renaming the column seemed the only sane thing to do.