Allow overriding the copyright year

[andreituicu]

As an author of the blogs, I would like in rare instanes to show a different year for the copyright notice.

Currently, the copyright notice will use the year of the Publication Date metadata.

Options for implementation:

Option 1

An optional new metadata row, that allows setting a different year then the one in the publication date.
The article-copyright block would check this metadata and use it if it is present, or fall back to the publication date when it is missing in most cases.

Option 2

A block configuration option.

--------------------------
| Article Copyright      |
--------------------------
| Year | 2023            |
--------------------------

Authors would add explicitly the block at the end of the word document, when they want to use a specific year for the copyright, different from the publication date.

The article-copyright block would check this metadata and use it if it is present, or fall back to the publication date when it is missing in most cases.

The autoblocking logic would check first that there isn't an article copyright block present, before trying to add it, so we don't end up with two copyrights.