feat(imports): import history and delete by import

Track imports in DB, show history in Data section, allow deleting
transactions of a specific import instead of clearing all.

frontend/src/api/import.ts

@@ -1,4 +1,7 @@
-import type { ImportStatementResponse } from '@family-budget/shared';
+import type {
+  ImportStatementResponse,
+  Import,
+} from '@family-budget/shared';
 import { api } from './client';
 
 export async function importStatement(
@@ -11,3 +14,13 @@ export async function importStatement(
     formData,
   );
 }
+
+export async function getImports(): Promise<Import[]> {
+  return api.get<Import[]>('/api/imports');
+}
+
+export async function deleteImport(
+  id: number,
+): Promise<{ deleted: number }> {
+  return api.delete<{ deleted: number }>(`/api/imports/${id}`);
+}