SV-230221 Improvements

[karikarshivani]

1. Update language to: The release <version> should be within the support window ending on <date>
2. Add more stringent regex to avoid conflicts (such as 8.1 vs 8.10): solution recommended in SV-230221 - Checks for Red Hat version 8.10 collide with 8.1 #27
3. Add a failure message or better date parsing for expected and got values