Fix: Allow to override ExportFormat with custom enum instance

[jeremiealvin]

Description

This code allow to override the ExportFormat enum by implementing a common interface on a new enum.
This allows the developer to create a custom exporter with other formats than the default specified in ExportFormat enum.

Functional changes

• Code style has been fixed by running the composer cs command.
• Changes have been tested to not break existing functionality.
• Documentation is up-to-date.

[danharrin]

Please rename it to ExportFormat and import it in the original enum as ExportFormatInterface

Please move it to Enums/Contracts