What does this PR change? What problem does it solve?

This PR adds [future] and [expired] labels to the post title in listings/single entry view, similarly to the existing [draft] logic.

Those labels will show up next to affected posts, if they are rendered (hugo -F -E was used). Helps to visually distinguish these post types during editing, just like [draft] does.

Example:

Logic is

• future: Date is set and after now
• expired: ExpiryDate is set and before now

If there's any way to get this determined directly by Hugo I'd love to use that instead, however I couldn't find something as convenient as .Draft for either future or expired state (still a very Hugo newbie).

Was the change discussed in an issue or in the Discussions before?

Closes #1119

PR Checklist

• This change adds/updates translations and I have used the template present here.
• I have enabled maintainer edits for this PR.
• I have verified that the code works as described/as intended.
• This change adds a Social Icon which has a permissive license to use it.
• This change does not include any CDN resources/links.
• This change does not include any unrelated scripts such as bash and python scripts.
• This change updates the overridden internal templates from HUGO's repository.