Replace `datacube.utils.cog` functions with `odc.geo.cog` functions

[vikineema]

The to_cog and write_cog functions in datacube.utils.cog will be deprecated in datacube 1.9 and will be removed in 2.0

• Frequently_used_code/Exporting_GeoTIFFs.ipynb

[lindangulopez]

Hi @vikineema are there alternative notebooks I can use?