[Sat6] Inconsistent use of scrollbars in the UI

Issue

In some areas, such as

• Content View > {View Name} > Yum Content > filters > {filter name} > affected repositories

there is only a single scroll bar which allows scrolling from the top of the pane to the bottom of the pane. This is a NICE experience.

In other areas, such as

• Activation keys > {key name} > subscriptions > add

there are multiple scroll bars, one for the whole pane, and one for just the subscriptions to add. This is NOT a nice experience