Use unique_ptr with LMDB resources to prevent leaks #2368

Job	Run time
Linux [UBSAN] [lmdb \| clang]	40m 41s
macOS [UBSAN] [lmdb \| clang]	37m 22s
Linux [ASAN] [lmdb \| clang]	42m 4s
macOS [ASAN] [lmdb \| clang]	28m 0s
Linux [ASAN_INT] [lmdb \| clang] (Errors Ignored)	40m 58s
macOS [TSAN] [lmdb \| clang]	32m 22s
Linux [TSAN] [lmdb \| clang]	41m 45s
macOS [UBSAN] [rocksdb \| clang]	41m 2s
Linux [LEAK] [lmdb \| clang]	42m 59s
macOS [ASAN] [rocksdb \| clang]	41m 35s
Linux [UBSAN] [rocksdb \| clang]	53m 34s
macOS [TSAN] [rocksdb \| clang]	52m 50s
Linux [ASAN] [rocksdb \| clang]	56m 21s
Linux [ASAN_INT] [rocksdb \| clang] (Errors Ignored)	57m 16s
Linux [LEAK] [rocksdb \| clang]	58m 21s
	11h 7m 10s

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