Implement SHA256 support for UserRebaseToRef
The UserRebateToRef RPC is still using libgit2 as implementation, which makes it incompatible with the SHA256 object format. Once converted to use plain Git, we need to adapt it to support SHA256.
The UserRebateToRef RPC is still using libgit2 as implementation, which makes it incompatible with the SHA256 object format. Once converted to use plain Git, we need to adapt it to support SHA256.