eosfs: Upload function does not take the lock into account

[glpatcern]

Found when testing the eosgrpc driver. The issue is that a locked file cannot be overwritten (eos introduced a proper protection for this, used by wopiserver with the xroot interface).

To fix this we need to change the fs.Upload() signature and pass the lock context along. I noted that in Reva edge, the Upload function was already modified to receive the whole GRPC request payload, which contains the lock.

This is not super urgent - in particular, we can deploy eosgrpc in production while keeping the wopiserver use the xroot interface - but it needs to be fixed in order to support locks from Reva (for WOPI apps but also for SWAN).

For the eos driver implementation, it will be enough to pass an extra eos.app HTTP header to EOS on PUT.