v2.0.3 of b012_data

Spring Boot-inspired Flutter package with auto-generated SQLite CRUD for your entities, plus binary file helpers (images, audio, video). Android, iOS, Linux, macOS, Windows. Changelog excerpt: - Added the static_and_variables.dartfile with a base64 image used for illustration in disc_example.dart. - Provided a more explicit use case of the method getEntityFileOnDiscin disc_example.dart. - Rearranged examplefor clearer use. - Rewrite README.mdfile. - Rename the getSommeColumnsFrom method to getSomeColumnsFrom.