f827196 coreos-download: fix inconsistent button and tab view

Authored and Committed by abai 4 years ago
    coreos-download: fix inconsistent button and tab view
    
    Fixes a bug that when users select a stream, the div section will be re-rendered into
    default "Cloud Launchable" instead of the tab users selected, creating inconsistency
    between tab button and tab view.
    
    To reproduce, select a tab other than "Cloud Launchable", say "For Cloud Operators".
    If we now select another stream, the div section below will be re-rendered with the
    default "Cloud Launchable".
    
    Also factors out the frequently used div IDs and deduplicates "toggleHidden" function.
    
    Signed-off-by: Allen Bai <abai@redhat.com>