Gauge w/ fixed format display

[jbudd]

@duaw

What really, really strucks me is that nobody disliked that behaviour so far.

There have been several discussions about this, eg https://discourse.nodered.org/t/cloning-d1-nodes-with-value-format-was-easy-what-is-the-best-d2-approach/96638

@duaw

a String cannot be fed to a gauge

Are you sure? It seems to work for me.

Alas, there are plenty of other reasons to shun the ui-gauge!