gnokey debug mode

[thehowl]

Currently, you can enable gnokey commands by setting window.gnokeyLog = true in your console. This was mostly a 10-minute addition, but as this is an educational tool for Gno I'd like to see this feature visible directly from the UI; kind of like a network tab, but for Gno.

This could actually be a small addition on top of gno-js-client which could be developed as a small pet library, for any other projects which may want to integrate it.