Visualize velocity data (e.g. wind) as streamlines and particles

[jtroberts]

Purpose

• Ability to visualize velocity data (geojson, gribjson, or geotiff) as streamlines or particles.

Proposed Changes

• Adds support for new "velocity" layer type that may be visualized as streamlines or particles (with placeholders to fully support arrows and wind barbs in the future).
• Supports reading velocity data as geojson, gribjson (streamlines only), or geotiff (arrows only).
• Velocity visualizations may be configured as desired in the configure tool. Streamlines use the leaflet-velocity library while particles use leaflet-rain.
• Incorporates js-colormaps for selecting color ramps for velocity visualizations.

Issues

• [New Feature]: Visualize velocity data (e.g. wind) as particles or streamlines #596

Testing

• Configured multiple wind datasets from weather models (ECMWF, GFS, and HRRR) and NASA products (ASCAT and OSCAR ocean currents) and visualized as streamlines and particles.
• Tested all new configuration options. Arrows and wind barbs are placeholders for now.

[tariqksoliman]

@jtroberts Is there any documentation I can follow to set this up and test it locally?

[jtroberts]

@jtroberts Is there any documentation I can follow to set this up and test it locally?

I need to add some documentation. I can also provide some sample data for you to test or point you to the wind server that we have currently under development.