WIP supported formats - remove reference to mobile-sdk, link ogr and gdal to mobile repo

[alex-cit]

fix #667

• removed references to mobile-sdk, there is one left in Licensing
• in Supported Formats , the list of supported OGR and GDAL drivers replaced by a link to https://github.com/MerginMaps/mobile/tree/master/docs . Should be the same done for supported QGIS providers? it also used to reference mobile-sdk repo

TODO:

• replace the link https://github.com/MerginMaps/mobile/tree/master/docs to the specific file supported_formats.txt (when it's created) or mention the file in the docs
• resolve reference to mobile-sdk in Licensing, if needed
• resolve supported QGIS providers, if needed