[scripts.upload] Make uploaded data a bit more obvious; Report size of uploaded material; Report URL of uploaded model/experiment; Move gitlab functions to dedicated module; Document dedicated module; Fix QA

Auto intersphinx would try to access "https://lightning.ai/lightning-docs/objects.inv" and would be
redirected to "https://lightning.ai/docs/app/stable/objects.inv" instead
of "https://lightning.ai/docs/pytorch/stable/objects.inv"