Implemented test for pricing utils. waiting for #417 to be completed

[ametel01]

PR Type:

• [x] Refactoring
• [x] Testing

Current Behavior:

The function apply_exponent_factor() was missing, and no tests were available for apply_impact_factor(). Resolves: #494

Updated Behaviour:

Testing parameters mirror those found in GMX's test.

Breaking Change Introduced?

No

[zarboq]

Hey ! Thanks but @StarkFishinator already had an ongoing PR on this here and he was assigned on the issue so we'll leave him the priority for the 'apply_exponent_factor' part

[ametel01]

I'll remove the changes in utils leaving only the tests, and draft this PR until utils are completed.