Add client-side custom filter support to glitch-soc

Port cdb101340a to glitch-soc,
but without dropping support for regexp filters yet.

app/javascript/flavours/glitch/styles/components/status.scss

@@ -111,6 +111,20 @@
   }
 }
 
+.status__wrapper--filtered {
+  color: $dark-text-color;
+  border: 0;
+  font-size: inherit;
+  text-align: center;
+  line-height: inherit;
+  margin: 0;
+  padding: 15px;
+  box-sizing: border-box;
+  width: 100%;
+  clear: both;
+  border-bottom: 1px solid lighten($ui-base-color, 8%);
+}
+
 .status__prepend-icon-wrapper {
   float: left;
   margin: 0 10px 0 -58px;