Finalize LaserGeometryRenderer

[francis-maes]

• Properly handle connected/disconnected lines
• Handle points mode: renderer should handle conversion of points into a laser sequence (c.f. Test the add_points functionality #23)
• Offer some control over the weight
• Support of 3D mask
• Handle gamma standardisation (c.f. Convert non-linear sRGB to linear sRGB (or vice versa) #21)

[francis-maes]

I made a pull request for this, let me know if it works!