Additional Expression Atlas datasets

Expand the number of datasets supported by including:

E-ERAD-475
E-MTAB-2770
E-PROT-13
E-GTEX-8
E-MTAB-2706
E-GEOD-5615
E-GEOD-5615
E-MTAB-513
E-MTAB-2836
E-MTAB-3579
E-MTAB-3827
E-MTAB-3358
E-MTAB-2801
E-MTAB-4840
E-GEOD-19520
E-GEOD-66048
E-MTAB-3578
E-PROT-3
E-GEOD-26284
E-MTAB-4344
E-MTAB-1733
E-MTAB-6814
E-MTAB-2800
E-GEOD-66048
E-MTAB-6798
