Catapult API : initial commit

[VellaRo]

add: get all players (x,y position) from an activity X. Also snychronises the timestamps if different start of timestamps (not tested yet)

[draabe]

Hi @VellaRo ,

thanks for your contribution. To be considered for merging, I'd encourage you to read our contributing guidelines and stick to the best practices we follow. I anticipate this is a rather larger addition you are planning, so maybe it makes more sense to start with an issue discussing your contribution.