feat(cli): Add ListOrganizations Feature

[DerBurri]

This commit introduces several improvements to the CLI command testing infrastructure:

• ListOrganizations: Implemented the first part of the Organizations API. The CLI is no able to list Organizations the User Token belongs too.
• ClientFactory Pattern: Implemented the ClientFactory pattern for ListOrgCmd and to allow for dependency injection of the Client improving test isolation and enabling more robust unit testing.
• Command Registration Tests: Added a unit test for AddListOrgCmd to verify that the command is correctly registered with its parent and has the expected properties (Use, Short, RunE).
• Output Format Validation: Enhanced ListOrganizations tests to capture os.Stdout and validate the actual JSON and YAML output against expected structures, ensuring correct serialization and presentation.
• Improved Error Handling Tests: Added test cases for ListOrgCmd to cover scenarios where the ClientFactory itself returns an error, ensuring comprehensive error propagation.
• Test Coverage Integration: Updated the Makefile with coverage and coverage-html targets to easily generate and view test coverage reports.