Added methods for benchmarking of commit/write ops

Added methods for benchmarking of efficiency of InMemoryDataTree for commits after each write.
Scenarios remain the same.

Change-Id: I71527f78d7762ba7baf7a7bef6471c2c81c26db0
Signed-off-by: Lukas Sedlak <lsedlak@cisco.com>
Merge "Added methods for benchmarking of commit/write ops"