Metadata: When parsing dates from exiftool, remap year 0 to 1

[carlonluca]

Year 0 is frequently used in exiftool but is not accepted in the Go time
package. time package uses year 1 for "zero" dates instead. Therefore,
remap year 0 from exiftool to year 1.

Acceptance Criteria:

• Features and improvements are fully implemented so that they can be released at any time without additional work
• Automated unit and/or acceptance tests have been added to ensure the changes work as expected and to reduce repetitive manual work
• Contributor License Agreement (CLA) has been signed

[CLAassistant]

All committers have signed the CLA.

[lastzero]

@carlonluca My apologies for the long delay! This looks good to me. Would you be able to resolve the conflicts so we can merge your changes automatically? If not, let me know so I can add the changes manually. Thank you very much! ❤️

[lastzero]

Thank you! ❤️