Allow patching unique non-put operations

[serathius]

What would you like to be added?

Currently only puts can be patched by robustness tests. This is because they were designed to be unique operations from the beginning. However, still some delete or compact operations are unique. We could patch them too.

We could modify the following code:

etcd/tests/robustness/validate/patch_history.go

Lines 28 to 32 in 54ddc02

	putRevision := putRevision(reports)
	persistedPutCount := countPersistedPuts(persistedRequests)
	clientPutCount := countClientPuts(reports)
	putReturnTime := uniquePutReturnTime(operations, persistedRequests, clientPutCount)
	return patchOperations(operations, putRevision, putReturnTime, clientPutCount, persistedPutCount)

To handle other operations too.

/cc @henrybear327 @nwnt @joshjms

Why is this needed?

Reduce linearization cost