A11y: add labels to previously unlabeled buttons, fix order

src/UI/BigComponents/OpenBackgroundSelectorButton.svelte

@@ -13,7 +13,8 @@
   export let hideTooltip = false
 </script>
 
-<MapControlButton on:click={() => state.guistate.backgroundLayerSelectionIsOpened.setData(true)}>
+<MapControlButton arialabel={Translations.t.general.labels.background}
+                  on:click={() => state.guistate.backgroundLayerSelectionIsOpened.setData(true)}>
   <Square3Stack3dIcon class="h-6 w-6" />
   {#if !hideTooltip}
     <Tr cls="mx-2" t={Translations.t.general.backgroundSwitch} />

src/UI/BigComponents/SelectedElementTitle.svelte

@@ -7,6 +7,7 @@
   import Translations from "../i18n/Translations";
   import Tr from "../Base/Tr.svelte";
   import { XCircleIcon } from "@rgossiaux/svelte-heroicons/solid";
+  import { ariaLabel } from "../../Utils/ariaLabel"
 
   export let state: SpecialVisualizationState;
   export let layer: LayerConfig;
@@ -50,8 +51,10 @@
       </div>
     </div>
 
-    <button on:click={() => state.selectedElement.setData(undefined)} class="border-none p-0">
-      <XCircleIcon class="h-8 w-8" />
+    <button on:click={() => state.selectedElement.setData(undefined)} 
+            use:ariaLabel={Translations.t.general.backToMap}
+            class="border-none p-0">
+      <XCircleIcon aria-hidden={true} class="h-8 w-8" />
     </button>
   </div>
 {/if}

src/UI/BigComponents/ThemeButton.svelte

@@ -92,7 +92,7 @@
       <Tr t={title} />
 
       {#if selected}
-        <span class="alert">
+        <span class="alert" aria-hidden="true">
           <Tr t={Translations.t.general.morescreen.enterToOpen} />
         </span>
       {/if}