feat: book cover thumbnails

In the 'Where is it?' modal, also display the cover for each record
found. Only do so if Show Covers for Editions is enabled in Grouped Work
Display Setting.

code/web/interface/themes/responsive/GroupedWork/copyDetails.tpl

@@ -3,6 +3,9 @@
 	<table class="table table-striped table-condensed itemSummaryTable">
 		<thead>
 		<tr>
+			{if !empty($showEditionCovers) && $showEditionCovers == 1}
+				<th></th>
+			{/if}
 			<th>{translate text="Available Copies" isPublicFacing=true}</th>
 			<th>{translate text="Edition" isPublicFacing=true}</th>
 			<th>{translate text="Location" isPublicFacing=true}</th>
@@ -13,6 +16,11 @@
 		{assign var=numRowsShown value=0}
 		{foreach from=$summary item="item"}
 			<tr {if !empty($item.availableCopies)}class="available" {/if}>
+				{if !empty($showEditionCovers) && $showEditionCovers == 1}
+					<td class="col-tn-2 col-md-2 col-lg-2">
+						<img src="{$recordDriver->getBookcoverUrl('small')}" class="img-thumbnail {$coverStyle}">
+					</td>
+				{/if}
 				{if $item.onOrderCopies > 0}
 					{if !empty($showOnOrderCounts)}
 						<td>{translate text="%1% on order" 1=$item.onOrderCopies isPublicFacing=true}</td>