refactor(frontend): use* 関数の格納場所のフォルダ名を composables に変更 (#16004)

* refactor(frontend): use* 関数の格納場所を正式名称（composables）に変更

* migrate

* move useLoading

packages/frontend/src/composables/use-loading.ts

@@ -0,0 +1,52 @@
+/*
+ * SPDX-FileCopyrightText: syuilo and misskey-project
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import { computed, h, ref } from 'vue';
+import MkLoading from '@/components/global/MkLoading.vue';
+
+export const useLoading = (props?: {
+	static?: boolean;
+	inline?: boolean;
+	colored?: boolean;
+	mini?: boolean;
+	em?: boolean;
+}) => {
+	const showingCnt = ref(0);
+
+	const show = () => {
+		showingCnt.value++;
+	};
+
+	const close = (force?: boolean) => {
+		if (force) {
+			showingCnt.value = 0;
+		} else {
+			showingCnt.value = Math.max(0, showingCnt.value - 1);
+		}
+	};
+
+	const scope = <T>(fn: () => T) => {
+		show();
+
+		const result = fn();
+		if (result instanceof Promise) {
+			return result.finally(() => close());
+		} else {
+			close();
+			return result;
+		}
+	};
+
+	const showing = computed(() => showingCnt.value > 0);
+	const component = computed(() => showing.value ? h(MkLoading, props) : null);
+
+	return {
+		show,
+		close,
+		scope,
+		component,
+		showing,
+	};
+};