## Archived labels
This adds the structure to allow for archived labels.
Archived labels are, just like closed milestones or projects, a medium to hide information without deleting it.
It is especially useful if there are outdated labels that should no longer be used without deleting the label entirely.
## Changes
1. UI and API have been equipped with the support to mark a label as archived
2. The time when a label has been archived will be stored in the DB
## Outsourced for the future
There's no special handling for archived labels at the moment.
This will be done in the future.
## Screenshots
![image](https://github.com/go-gitea/gitea/assets/80308335/208f95cd-42e4-4ed7-9a1f-cd2050a645d4)
![image](https://github.com/go-gitea/gitea/assets/80308335/746428e0-40bb-45b3-b992-85602feb371d)
Part of https://github.com/go-gitea/gitea/issues/25237
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Co-authored-by: delvh <dev.lh@web.de>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>