feat(tiler-sharp): directly resize/resample DEM inputs rather than RGBA outputs

[blacha]

Motivation

Resizing/resmapling after the pipelines are applied is very wasteful as we apply a pipeline then only use a very low percentage of data.

Modification

Adds a direct resize/resample on the input data rather than resampling the output.

Checklist

If not applicable, provide explanation of why.

• [ ] Tests updated
• [ ] Docs updated
• [ ] Issue linked in Title