See #8222 for context (loosely related to #4595).
## Implemented changes
The conversion logic is kept in the frontend and the related npm libraries are lazy-loaded (unchanged).
### Show some tabs on the preview of the `CITATION.*` file to switch between the formats:


### Convert the "Cite repository" to a simple link to the citation file
So that this change can be considered non-breaking
## Current state (before this PR)
The last non-test call of `git.Blob.GetBlobContent` is made to retrieve the content of an eventual CITATION file.
This is available in the `...` menu near the clone URL:

And is displayed as a popup:

Co-authored-by: 0ko <0ko@noreply.codeberg.org>
Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/9103
Reviewed-by: Gusted <gusted@noreply.codeberg.org>
Reviewed-by: 0ko <0ko@noreply.codeberg.org>
Co-authored-by: oliverpool <git@olivier.pfad.fr>
Co-committed-by: oliverpool <git@olivier.pfad.fr>