feat: timestamp getters for PostObjectInterface

[thorbrink]

This pull request introduces methods to retrieve the published and modified timestamps for post objects across several classes. The changes ensure consistency and compatibility with the PostObjectInterface.

Addition of timestamp retrieval methods:

• library/PostObject/PostObjectInterface.php: Added getPublishedTime and getModifiedTime methods to the interface.

Implementation of timestamp retrieval methods in various decorators:

• library/PostObject/Decorators/BackwardsCompatiblePostObject.php: Implemented getPublishedTime and getModifiedTime methods.
• library/PostObject/Decorators/IconResolvingPostObject.php: Implemented getPublishedTime and getModifiedTime methods.
• library/PostObject/Decorators/PostObjectFromOtherBlog.php: Implemented getPublishedTime and getModifiedTime methods.
• library/PostObject/Decorators/PostObjectFromWpPost.php: Implemented getPublishedTime and getModifiedTime methods, using strtotime to convert WP post dates to timestamps.
• library/PostObject/Decorators/PostObjectWithSeoRedirect.php: Implemented getPublishedTime and getModifiedTime methods.

Addition of unit tests:

• library/PostObject/Decorators/PostObjectFromWpPost.test.php: Added unit tests to verify the functionality of getPublishedTime and getModifiedTime methods.

[sonarqubecloud]

Quality Gate passed

Issues
2 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud