add svg icons, make event display buttons toggleable

web/src/components/events/EventContainer.tsx

@@ -118,20 +118,21 @@ export const EventContainer = ({
     <div className={styles.events}>
       <div className={styles.eventWrapper}>
         <div className={styles.displayOptions}>
-          <button onClick={() => setMode(null)} className="button secondary">
+          <button onClick={() => setMode(null)} className="button toggler hasIcon" data-active={mode === "list"}>
             <span>Vis liste</span>
-            <Icon />
+            <Icon type="list" />
           </button>
           <button
             onClick={() => setMode("calendar")}
-            className="button secondary"
+            className="button toggler hasIcon"
+            data-active={mode === "calendar"}
           >
             <span>Vis kalender</span>
-            <Icon />
+            <Icon type="calendar" />
           </button>
           <button onClick={toggleFilter} className="button tertiary">
             <span>Filter</span>
-            <Icon />
+            <Icon type="filter" />
           </button>
         </div>
         <EventFilter