kv: disallow Put/Delete requests after a DeleteRange request in a batch

**Describe the problem**

@stevendanna pointed me to https://github.com/cockroachdb/cockroach/issues/71236 earlier today. The issue there talks about intents from blind Puts, but I think the hazard also applies to blind Deletes (`DeleteRequests`).

We should validate that once we encounter a `DeleteRange` in a batch, there isn't a subsequent `Put` or `Delete` request after it. This should be fine, as SQL currently doesn't construct batches like such. Moreover, even when flushing the buffer when running with buffered writes, we'll only ever prepend to a batch that has `DeleteRange` requests.

Jira issue: CRDB-49220