Replace rasterio with qgis processing module in cplus-core

[danangmassandy]

Rasterio is used in cplus-core for these two methods:

• normalize_raster_layer
• replace_nodata_value_from_reference

However, when we build the plugin with cplus-core library (PR #541), the rasterio package is included and the total zip file becomes 128 MB which is not ideal. During plugin startup, there was also error from rasterio: ModuleNotFoundError: No module named 'rasterio._base'

I think we should change the implementation of above two methods to use QGIS processing module similar to what we currently have in the plugin for replace_no_data code.