fix: remove functional template

Fixes #311

src/client/theme-default/components/icons/ArrowLeft.vue

@@ -1,4 +1,4 @@
-<template functional>
+<template>
   <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24">
     <path
       d="M19,11H7.4l5.3-5.3c0.4-0.4,0.4-1,0-1.4s-1-0.4-1.4,0l-7,7c-0.1,0.1-0.2,0.2-0.2,0.3c-0.1,0.2-0.1,0.5,0,0.8c0.1,0.1,0.1,0.2,0.2,0.3l7,7c0.2,0.2,0.5,0.3,0.7,0.3s0.5-0.1,0.7-0.3c0.4-0.4,0.4-1,0-1.4L7.4,13H19c0.6,0,1-0.4,1-1S19.6,11,19,11z"

src/client/theme-default/components/icons/ArrowRight.vue

@@ -1,4 +1,4 @@
-<template functional>
+<template>
   <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24">
     <path
       d="M19.9,12.4c0.1-0.2,0.1-0.5,0-0.8c-0.1-0.1-0.1-0.2-0.2-0.3l-7-7c-0.4-0.4-1-0.4-1.4,0s-0.4,1,0,1.4l5.3,5.3H5c-0.6,0-1,0.4-1,1s0.4,1,1,1h11.6l-5.3,5.3c-0.4,0.4-0.4,1,0,1.4c0.2,0.2,0.5,0.3,0.7,0.3s0.5-0.1,0.7-0.3l7-7C19.8,12.6,19.9,12.5,19.9,12.4z"

src/client/theme-default/components/icons/OutboundLink.vue

@@ -1,4 +1,4 @@
-<template functional>
+<template>
   <svg
     class="icon outbound"
     xmlns="http://www.w3.org/2000/svg"