Re-organise assets to be closer to their respective uses.

src/components/common/ChannelIcon.tsx

@@ -8,7 +8,8 @@ interface Props extends IconBaseProps<Channels.GroupChannel | Channels.TextChann
     isServerChannel?: boolean;
 }
 
-const fallback = '/assets/group.png';
+import fallback from './assets/group.png';
+
 export default function ChannelIcon(props: Props & Omit<JSX.HTMLAttributes<HTMLImageElement>, keyof Props>) {
     const client = useContext(AppContext);
 

src/components/common/UserIcon.tsx

@@ -47,7 +47,8 @@ const VoiceIndicator = styled.div<{ status: VoiceStatus }>`
     ` }
 `;
 
-const fallback = '/assets/user.png';
+import fallback from './assets/user.png';
+
 export default function UserIcon(props: Props & Omit<JSX.SVGAttributes<SVGSVGElement>, keyof Props>) {
     const client = useContext(AppContext);