web/ProcessingQueue: use new types and states, refactor

- added a dedicated ui debug button
- fixed scrolling (content is no longer cutting off weirdly)
- moved stub to its own component
- moved all permanent strings to localization

web/src/components/queue/ProcessingQueueStub.svelte

@@ -0,0 +1,44 @@
+<script lang="ts">
+    import { t } from "$lib/i18n/translations";
+    import Meowbalt from "$components/misc/Meowbalt.svelte";
+
+    const stubActions = ["download", "remux"];
+
+    const randomAction = () => {
+        return stubActions[Math.floor(Math.random() * stubActions.length)];
+    };
+</script>
+
+<div class="queue-stub">
+    <Meowbalt emotion="think" />
+    <span class="subtext stub-text">
+        {$t("queue.stub", {
+            value: $t(`queue.stub.${randomAction()}`),
+        })}
+    </span>
+</div>
+
+<style>
+    .queue-stub {
+        --base-padding: calc(var(--padding) * 1.5);
+        font-size: 13px;
+        font-weight: 500;
+        color: var(--gray);
+        display: flex;
+        flex-direction: column;
+        align-items: center;
+        justify-content: center;
+        padding: var(--base-padding);
+        padding-bottom: calc(var(--base-padding) + 16px);
+        text-align: center;
+        gap: var(--padding);
+    }
+
+    .queue-stub :global(.meowbalt) {
+        height: 120px;
+    }
+
+    .stub-text {
+        padding: 0;
+    }
+</style>