Use a fixed height box for validations

[Ana Krivokapić]

It would be an improvement if we could use a fixed height box (based on the browser height) for the validations list on the right. These sections could be accordions with scroll bars. This way the user would never need to scroll the entire page to see them all, they would still have the deployment plan context on the left at all time. Please see the Fixed Height Accordion in PatternFly for an example: https://www.patternfly.org/widgets/#accordion