[CO #5,6] Cover MainNewStreetcode component with unit tests

Write unit test for creating a streetcode component:
- test for creation with only all required fields
- test for creation with all possible fields and entities
- load image and audio from project assets (create a folder for_tests if not exists). Use both small and large images with .webp format
- check if correct entity was sent to backend

Write unit test for updating a streetcode component:
- check if all data that was accepted from mocked get request was set in corresponding fields

Mock all needed request to backend such as Create image request and others