Add meter widget

[GregJHarris]

Add a meter widget, this uses react-gauge-component.

• We use a semi-circular gauge for all width / height ratios.

Some examples:

and corresponding Phoebus screens:

[abigailalexander]

Looks great overall, the scales seem good. I agree with not stretching the meter to odd proportions and maintaining the width/height ratio. One small fix - it seems like scaledWidth isn't being properly applied sometimes and the widget isn't taking up the full space available (nor being centered in the available space). I've attached a picture to show the difference between Phoebus and cs-web-lib for a widget with dimensions w: 440, h:370


As a result of the widget being smaller than expected, the scale is quite bunched up.

[GregJHarris]

Thanks @abigailalexander. I've fixed the sizing and improved the formatting of the tick labels, so that if the number strings are 4 characters or more long, every other tick has a label.

[abigailalexander]

Looks great now, thanks for making that change!