iso-surface finalist with caps, slices & spaceframe display on uniform or non-uniform coordinates

[archmoj]

Supersedes #3340 i.e. using neither gl-isosurface3d nor isosurface modules!
Totally rewritten and based on plotly.js most recent source code for mesh3d trace.
Iso-surfacea, caps, horizontal & vertical slices as well as 3-D spaceframe between iso-min & iso-max ranges of volume data could be visualised using this new trace.
Now non-uniform coordinates are also supported.

Various options and data could be tested using this demo.

@plotly/plotly_js

[archmoj]

@etpinard simply for your info:
Now the slices perform interpolations between axis points thanks to 436c0d9.
Later on the road, the function may possibly be applied for creating slices in directions other than (x|y|z) and with inclination.

[etpinard]

@archmoj You're getting really close! I think the only thing missing a one "simple" mock with multiple isosurface traces on the same scene.

[etpinard]

Oh and one more thing: add one isosurface mock (I'd pick the one that renders the fastest) to this list

plotly.js/test/jasmine/assets/mock_lists.js

Lines 50 to 61 in cc45972

	varglMockList=[
	['gl2d_heatmapgl',require('@mocks/gl2d_heatmapgl.json')],
	['gl2d_line_dash',require('@mocks/gl2d_line_dash.json')],
	['gl2d_parcoords_2',require('@mocks/gl2d_parcoords_2.json')],
	['gl2d_pointcloud-basic',require('@mocks/gl2d_pointcloud-basic.json')],
	['gl3d_annotations',require('@mocks/gl3d_annotations.json')],
	['gl3d_set-ranges',require('@mocks/gl3d_set-ranges.json')],
	['gl3d_world-cals',require('@mocks/gl3d_world-cals.json')],
	['gl3d_cone-autorange',require('@mocks/gl3d_cone-autorange.json')],
	['gl3d_streamtube-simple',require('@mocks/gl3d_streamtube-simple.json')],
	['glpolar_style',require('@mocks/glpolar_style.json')],
	];

[etpinard]

Ok. Tests are passing!

Time to merge this thing! 💃 💃 💃

Awesome work @archmoj !!

[archmoj]

Many thanks @etpinard for the help & review.
Merging...