Add allFiles method to get an object of multipart files

• test: attempt to fix the failing test coz of stream race conditions b3fd09c
• test: add test for request.allFiles method 237102b
• chore: update dependencies ee28fe3
• feat(file): add isMultipartFile flag to know if file is an instance of file 7ba14cf
• feat: add allFiles method to request class a6c7034

v3.2.1...v3.2.2