[BUG] Qualification: Jobs with UDFs may have inaccurate speedups

[kuhushukla]

Describe the bug
SQL queries with UDFs are hard to quantify in terms of what is the actual cost of them falling back to the CPU. Recently some of the customers reported Q tool speedup values of 3x while the actual runtimes were 2x slower.

Expected behavior
We should mark the whole stage as a CPU fallback and penalize UDF SQL queries heavily to indicate them as bad migration candidates.

[amahussein]

@nartal1

FWIW, Addition context:

#1271

[amahussein]

@nartal1 is this still an issue or should it be closed with a comment of your final findings?

[nartal1]

Adding penalty for stages with UDF's is done and UDF's are detected correctly in the qualification tool. But it didn't improve the total speedup factor as we do the average of speedups across all stages. I would still keep it open but lower the priority of it to investigate if other improvements can be done.

[amahussein]

Closing this as speedup has shifted to the QualX now