Resolve reference OIDs with a single process

TransactionManager is currently calling ResolveRevision for each reference the transaction is updating to figure out the current value of the reference. This leads to spawning a rev-parse command for each reference which is very inefficient if a transaction contains more than one reference.

Use the existing checkObjects function to resolve the old values of the references using a single command.

Before the optimization with transaction updating 1000 references, we're spending most of the time resolving the references.

Before we were resolving references for 2.4s

Afterwards we're resolving references for 57ms