MM-62933 Revert position of post menu to match earlier versions (#30190)

Co-authored-by: Mattermost Build <build@mattermost.com>

webapp/channels/src/sass/components/_post-menu.scss

@@ -11,6 +11,11 @@
     padding: 4px;
     border: 1px solid transparent;
     border-radius: 4px;
+
+    // Counteract the margins added to ul in _typography.scss
+    margin-top: 0;
+    margin-bottom: 0;
+
     list-style: none;
     white-space: normal;
 }

webapp/channels/src/sass/components/_search.scss

@@ -335,12 +335,10 @@
     right: 0;
     font-size: 13px;
 
-    a {
-        vertical-align: top;
-    }
-
     .search-item__jump {
         position: relative;
+        display: block;
+        height: 100%;
         padding: 5px 4px 0;
         border-radius: 4px;
         color: rgba(var(--center-channel-color-rgb), 0.4);