Add model selection feature to all hydrology charts

[cstephen]

Closes #146.

This PR adds the same model selection feature we have for other ARDAC's items to all hydrology charts.

To test, first uncomment the hydrology slugs in slugs.d.ts so the corresponding items are accessible:

| 'hydrology-evap'
| 'hydrology-glacier-melt'
| 'hydrology-iswe'
| 'hydrology-runoff'
| 'hydrology-sm'
| 'hydrology-snow-melt'

Then run ARDAC Explorer against the development API:

export SNAP_API_URL=https://development.earthmaps.io
npm run dev

Then enter a location (e.g, "Fairbanks") into any of these hydrology data x-ray items to load the charts, then experiment with selecting different models to verify that the charts react accordingly:

http://localhost:3000/item/hydrology-evap
http://localhost:3000/item/hydrology-glacier-melt
http://localhost:3000/item/hydrology-iswe
http://localhost:3000/item/hydrology-runoff
http://localhost:3000/item/hydrology-sm
http://localhost:3000/item/hydrology-snow-melt