remove `transforms` attribute from PlotSchema for traces that don't support them

[antoinerg]

In the process of reviewing PR #3158, @etpinard pointed out that some traces don't support transforms yet it's listed in their PlotSchema (#3158 (comment))

Note that they are properly removed from _fullData:

plotly.js/src/plots/plots.js

Lines 1224 to 1230 in 0124828

	plots.supplyTransformDefaults = function(traceIn, traceOut, layout) {
	// For now we only allow transforms on 1D traces, ie those that specify a _length.
	// If we were to implement 2D transforms, we'd need to have each transform
	// describe its own applicability and disable itself when it doesn't apply.
	// Also allow transforms that make their own data, but not in globalTransforms
	if(!(traceOut._length || hasMakesDataTransform(traceIn))) return;

[etpinard]

Somewhat overlaps with #2908, in particular #2908 (comment)

[antoinerg]

Closing in favor of #2908