调整 api 目录，代码优化

src/api/tools/picture.js

@@ -0,0 +1,25 @@
+import request from '@/utils/request'
+
+export function del(id) {
+  return request({
+    url: 'api/pictures/' + id,
+    method: 'delete'
+  })
+}
+
+export function delAll(ids) {
+  return request({
+    url: 'api/pictures/',
+    method: 'delete',
+    data: ids
+  })
+}
+
+export function downloadPicture(params) {
+  return request({
+    url: 'api/pictures/download',
+    method: 'get',
+    params,
+    responseType: 'blob'
+  })
+}