[BUGFIX] EXT:form - fix design glitches of new element modal

Streamline the markup of the new element modal of the form editor and
fix some style glitches due to side effects with other extensions.

Resolves: #82444
Releases: master, 8.7
Change-Id: Ifceac76a70dd4744f52da3b08ca8baea5f4adb7d
Reviewed-on: https://review.typo3.org/55832
Reviewed-by: Björn Jacob <bjoern.jacob@tritum.de>
Tested-by: Björn Jacob <bjoern.jacob@tritum.de>
Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Oliver Hader <oliver.hader@typo3.org>
Tested-by: Oliver Hader <oliver.hader@typo3.org>

typo3/sysext/form/Resources/Private/Backend/Partials/FormEditor/Modals/InsertElements.html

@@ -3,26 +3,24 @@
 	<div class="t3-form-x-component-inner-wrapper">
 		<f:for each="{insertRenderablesPanelConfiguration}" as="insertRenderablePanelConfiguration">
 			<f:if condition="{insertRenderablePanelConfiguration.key} != 'page'">
-				<div class="row">
+				<div class="row media">
 					<div class="col-sm-12">
 						<h4 class="t3-form-group-{insertRenderablePanelConfiguration.key}">
 							<span>{insertRenderablePanelConfiguration.label}</span>
 						</h4>
 					</div>
 					<f:for each="{insertRenderablePanelConfiguration.elements}" as="element">
-						<div class="col-sm-4 btn-group">
+						<div class="col-sm-4 form-group">
 							<a class="t3-form-group-{insertRenderablePanelConfiguration.key} t3-form-type-{element.cssKey} btn btn-default btn-block" title="{element.key}" data-element-type="{element.key}">
 								<span class="pull-left">
 									<core:icon identifier="{element.iconIdentifier}" alternativeMarkupIdentifier="inline" />
 									<span>{element.label}</span>
 								</span>
 								<span class="clearfix"></span>
 							</a>
-							<hr>
 						</div>
 					</f:for>
 				</div>
-				<hr>
 			</f:if>
 		</f:for>
 	</div>