Define EventLogging schemas in MobileFrontend

Note all are dormant until wgUseEventLogging is set to true
(this is the case on Wikimedia servers)

Important: Should be deployed at same time as:
Ifbb052bb699e45a6ef1caef588f4e20bb85ccfa9

Change-Id: I8d750d4f82fbcfdfddd40cc8d78d35720f396bcf