Remove conflicting CSS rules on notifications, improve notifications table (#23565) (#23621)

Backport #23565 by @silverwind

Dropdowns on `/notifications/subscriptions` before and after:

<img width="157" alt="Screenshot 2023-03-18 at 20 37 12"
src="https://user-images.githubusercontent.com/115237/226133906-e4ad6a0a-de24-4324-8e1d-94081d23fe85.png">
<img width="152" alt="Screenshot 2023-03-18 at 20 41 29"
src="https://user-images.githubusercontent.com/115237/226134038-c3946c32-a424-4b92-ad15-890e1036cafe.png">

These selectors are meant to target the notification list which I
improved:

<img width="1145" alt="Screenshot 2023-03-19 at 01 52 11"
src="https://user-images.githubusercontent.com/115237/226147907-1c35736a-4bc9-4698-9813-21a20a1d2106.png">
<img width="1148" alt="Screenshot 2023-03-19 at 01 54 17"
src="https://user-images.githubusercontent.com/115237/226147920-626dbd84-11d3-48db-a177-6d808e3212c0.png">

templates/user/notification/notification_div.tmpl

@@ -35,26 +35,26 @@
 							{{$issue := .Issue}}
 							{{$repo := .Repository}}
 							<tr id="notification_{{.ID}}">
-								<td class="collapsing" data-href="{{.Link}}">
+								<td class="collapsing gt-pl-4" data-href="{{.Link}}">
 									{{if eq .Status 3}}
-										<span class="blue">{{svg "octicon-pin"}}</span>
+										{{svg "octicon-pin" 16 "text blue"}}
 									{{else if not $issue}}
-										<span class="gray">{{svg "octicon-repo"}}</span>
+										{{svg "octicon-repo" 16 "text grey"}}
 									{{else if $issue.IsPull}}
 										{{if $issue.IsClosed}}
 											{{if $issue.GetPullRequest.HasMerged}}
-												<span class="purple">{{svg "octicon-git-merge"}}</span>
+												{{svg "octicon-git-merge" 16 "text purple"}}
 											{{else}}
-												<span class="red">{{svg "octicon-git-pull-request"}}</span>
+												{{svg "octicon-git-pull-request" 16 "text red"}}
 											{{end}}
 										{{else}}
-											<span class="green">{{svg "octicon-git-pull-request"}}</span>
+											{{svg "octicon-git-pull-request" 16 "text green"}}
 										{{end}}
 									{{else}}
 										{{if $issue.IsClosed}}
-											<span class="red">{{svg "octicon-issue-closed"}}</span>
+											{{svg "octicon-issue-closed" 16 "text red"}}
 										{{else}}
-											<span class="green">{{svg "octicon-issue-opened"}}</span>
+											{{svg "octicon-issue-opened" 16 "text green"}}
 										{{end}}
 									{{end}}
 								</td>

web_src/css/user.css

@@ -85,27 +85,6 @@
   padding: 8px 15px;
 }
 
-.user.notification .svg {
-  float: left;
-  font-size: 2em;
-}
-
-.user.notification .svg.green {
-  color: var(--color-green);
-}
-
-.user.notification .svg.red {
-  color: var(--color-red);
-}
-
-.user.notification .svg.purple {
-  color: var(--color-purple);
-}
-
-.user.notification .svg.blue {
-  color: var(--color-blue);
-}
-
 .user.notification .content {
   float: left;
   margin-left: 7px;
@@ -170,4 +149,13 @@
 
 #notification_div .tab.segment {
   overflow-x: auto;
+  padding: 0;
+}
+
+#notification_div .menu .active.item {
+  background: var(--color-box-body);
+}
+
+#notification_table {
+  border: none;
 }