gsea: fixing expression explorer

The EE uses the package shinyjqui. This package has changed data structures which caused the EE to not work properly for the most recent version 0.4.0 of this package. Searching + adapting EE to make it run with all versions of shinyjqui until v0.4.0. I've added expression_explorer.yml with a minimal Conda env to run the EE. On top, I've change the EE to not depend anymore on devtools and additional SCF internal scripts which includes to load libraries with library statements rather then load_pack statements.