improve confusing/frustrating Revisions list curation interactions

[jmcmichael]

The Revisions list currently exhibits interaction behavior that can be confusing and/or frustrating while selecting multiple revisions for moderation:

• in order to select all revisions, curators must click a small checkbox in each header
• clicking anywhere else in the revision header causes the accordion component to hide the revision detail panel
• loading more revisions causes all the checkboxes to revert to unchecked

Possible solutions:

• adjust the accordion show/hide behavior such that it is only activated when clicking the header reveal caret at the left
• ensure that selected revisions remain selected after appending more loaded revisions
• add a 'Select All Revisions' button (note that w/o additional API interaction, it will only select visible revisions)