For non-majority write concerns (with a number or tag), we are going to preserve the read-your-write assumption that customers may rely on. Non-majority write concern waits for the specified set of nodes to have their lastDurable (j: true) or lastApplied (j: false) to advance past the write. To preserve the read-your-write assumption, we need to change the j: true case to use min(lastDurable, lastApplied) because oplog entries being durable no longer implies being applied.

This should be gated by feature flag.

We may need to come up with a general wait-for-timestamp mechanism that also works for SERVER-85704.