ClusterFindCmdBase::parse does not actually parse the command request, and instead that work is deferred until the command invocation is run, which is unexpected. Deferring parsing will have also a performance cost once SERVER-85791 is merged, since the generic arguments need to be parsed in parse, so deferring will result in them being parsed twice.

We should update ClusterFindCmd's implementation to actually parse the request in its parse method. The shard's implementation of find has already been updated to do this in SERVER-86084, so this will also make the two command implementations more consistent.