Fix for unexpected zero value last edit dates in segment archiving

[bx80]

Description:

If a segment has a last edited date of 0000-00-00 then segment archiving will fail with the exception: The date xxx is a date before first website was online.

This is caused by attempting to parse the invalid 0000-00-00 date string. This PR adds a simple check to avoid parsing if the last edited date is null or zero along with some additional tests to check an exception isn't thrown when zero dates are provided.

This is a 4.x back port of #21189

ref: L3-522

Review

• Functional review done
• Potential edge cases thought about (behavior of the code with strange input, with strange internal state or possible interactions with other Matomo subsystems)
• Usability review done (is anything maybe unclear or think about anything that would cause people to reach out to support)
• Security review done
• Wording review done
• Code review done
• Tests were added if useful/possible
• Reviewed for breaking changes
• Developer changelog updated if needed
• Documentation added if needed
• Existing documentation updated if needed