[BUGFIX] Enable line-wraps in backend preview tables

Resources/Private/Templates/Backend/Tabs.html

 {namespace be=TYPO3\CMS\Backend\ViewHelpers}
 {namespace core=TYPO3\CMS\Core\ViewHelpers}
 
+<style type="text/css">
+	.backend-preview-table > tbody > tr > th {
+		white-space: normal;
+	}
+</style>
+
 <br/>
 
-<table class="table table-striped table-bordered">
+<table class="table table-striped table-bordered backend-preview-table">
 	<f:render partial="PluginDataTableHeader"/>
 	<tbody>
 	<tr>