ASA: Add a Humidex Layer

**As a** Weather Forecaster

**I need** To visualize the Humidex Layer

**So That** I can better alert BCWS staff re: potential heat exposure risks

**Acceptance Criteria**
- [ ] Given (Context), When (action carried out), Then (expected outcome)
- [ ] Given (Context), When (action carried out), Then (expected outcome)

**Additional Context**
- Subject Matter Expert for User Research: EC: " The heat exposure threshold is humidex > 35. Heat Exposure should be in hourly timesteps"
- [Option1 HRDPS Humidex layer available in GRIB2](https://eccc-msc.github.io/msc-animet/?layers=HRDPS.CONTINENTAL_HMX;0.75;0;1;0;1&extent=-21187132,938490,-1216482,10982552&play=1)
- [Option2 WMS layer: Name HRDPS.CONTINENTAL - Humidex at 2 m above ground
](https://geo.weather.gc.ca/geomet?version=1.3.0)
- https://intranet.gov.bc.ca/assets/intranet/bcws-intranet/resource-centre/02-standards-sopg-manuals/safety/exposure_control_plan_heat_injury.pdf?
- TBD ASA Go layer

**Definition of Done**
https://github.com/bcgov/wps/wiki/Definition-of-Done

Start by reviewing the HRDPS Humidex GRIB2 and WMS references, the heat-exposure threshold of humidex >35, and the requirement for hourly timesteps. Identify how the ASA Go layer is expected to integrate, then define concrete acceptance criteria for displaying and validating the layer before implementation.

Written by the indexing model from the issue text.