PI code and its version Management to external server(other than PI environment)

Recently we have received a request to keep our ,most recent, working code PI of ESR and ID into some external repository, which seems to me very new. As i never did this, nor received such request in my previous 8-10 projects of SAP PI/PO, hence checking.

1) Is there any option to put/upload PI code of ESR and ID into some external version Management system/servers, like SVN etc. ?

2) I understand, we can put .tpz file extensions to any external folders, but is that the correct way of keeping PI code externally.

Thanks

Pradeep