Set up performance testing

[kissgyorgy]

We need to measure how fast unblob as a whole can operate and what strategy can speed up extraction significantly.
Example question we want to answer: Which is faster? Matching on all YARA patterns at once or iterating on the file multiple times with less patterns?

Measure different scenarios:

• One big file with few smaller files inside
• Lots of small files concatenated and inside
• Multiple big files concatenated and inside
• Refact the priority handling by concatenating all YARA rules and handle the match results by priority instead of scanning a file multiple times. Measure the difference on various files.

[vlaci]

We should measure how much wall time the different extraction steps take, e.g. Yara matching, chunk calculation, carving, extraction and so on.

[kissgyorgy]

There is pytest-benchmark which we can use to write benchmark tests with some special markers which would be ignored by default but can be easily selected to run.