Remove raster checker

[leendertvanwolfswinkel]

threedi_modelchecker has been adapted (v 0.32) to include raster checks. Tasks for 3Di Models & Simulations:

• [x] Remove all UI elements related to the raster checker from the Upload wizard
• [x] Remove all code related to the raster checker

No extra code should be required for the new raster checks to be performed (as long as threedi_modelchecker v0.32 or higher is available)

[ldebek]

@leendertvanwolfswinkel Changes available for testing on branch: https://github.com/nens/threedi-api-qgis-client/tree/upload_wizard_checker_update