Allow range deletions in `*TransactionDB` only when safe (#7929)

Allow range deletions in `*TransactionDB` only when safe (#7929)

Summary:
Explicitly reject all range deletions on `TransactionDB` or `OptimisticTransactionDB`, except when the user provides sufficient promises that allow us to proceed safely. The necessary promises are described in the API doc for `TransactionDB::DeleteRange()`. There is currently no way to provide enough promises to make it safe in `OptimisticTransactionDB`.

Fixes https://github.com/facebook/rocksdb/issues/7913.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7929

Test Plan: unit tests covering the cases it's permitted/rejected

Reviewed By: ltamasi

Differential Revision: D26240254

Pulled By: ajkr

fbshipit-source-id: 2834a0ce64cc3e4c3799e35b885a5e79c2f4f6d9