fix: duplicate shared/constants/ into client repo

shared/constants/upload-limits.js

@@ -0,0 +1,9 @@
+const MB = 1024 * 1024
+
+export const ADMIN_UPLOAD_IMAGE_MAX_FILE_BYTES_DEFAULT = 20 * MB
+
+export const ADMIN_UPLOAD_IMAGE_MAX_BYTES = 20 * MB
+
+export function formatAdminImageMaxSizeHint() {
+  return '20 МБ'
+}