Set `normalize` to `false` on GeoTIFF sources

[mfisher87]

https://openlayers.org/en/latest/apidoc/module-ol_source_GeoTIFF-GeoTIFFSource.html

By default, GeoTIFF sources' style expressions span normalized values 0-1. This is why it's challenging to restore the color stops for singleband pseudocolor from state. If we turn off normalization, we will be able to store raw data values, e.g. 0-2500, for our color stops in our style expressions. This will require less code to translate from raw values to normalized values when building style expressions, and enable us to load the style expressions to stops in the symbology UI.