alerts: Calculate after sample size dynamically

• Rank the traces per job based on the variance
• Normalize the value in range [0,1]
• Apply linear interpolation between minimal and maximum sample size for after scenario
• Increase before scenario sample size from 30 to 50
• Use only the numerator from the CV based Lerh's formula, as dividing by the logarithm of means makes sample sizes explode and lose precision, since more variable data were requiring relatively less samples.
  • See more https://rstudio-pubs-static.s3.amazonaws.com/201750_c17bc51d8553452d997ba4d258b0249f.html#sample-size