Regex Number Parsing Errors for netcoreapp 3.0

[Anipik]

There are two issue that we face while matching the baseline files while running tests for netcoreapp3.0

• The regex treats -0 and 0 differently. We may need to modify the regex for filtering the numbers to treat -0 and 0 same.
• Some numbers are in written in the baseline file in the form of exponentials eg 5.011722E-35 They are not picked up by the regex. so while matching these numbers we do an exact match rather than a floating number comparison with some buffer which fails for netcoreapp3.0

cc @danmosemsft @tannergooding @eerhardt @shauheen @codemzs