Replace default fmt::Display on core::Hash (#2325)
Replace default fmt::Display on core::Hash (#2325)

* Print block hash in TUI partially
* Implement fmt::Display for core::Hash
* Show first 12 digits of Hash
* Show full hex string of hash in fmt::Debug for core::Hash
* Strip hash in fmt::Debug and use fmt::Debug for fmt::Display
yeastplume/grin,yeastplume/grin