Improve the way we generate version numbers

The version number shown on the "About Jami" pop-up currently simply gives the date and time at which this particular version was compiled. E.g. for yesterday's (2024-08-01) nightly release, it looks like this:

On Linux at least, this doesn't necessarily match the tag generated by Jenkins when building the release, which seems to correspond to the date at which the release's commit was merged. E.g. the 2024-08-01 release is actually tagged as nightly/20240726.0.

We should change the way we generate versions numbers and/or tags to make sure that the two always stay in sync. It should be easy for devs to find the commit corresponding to any particular version.

added packaging platformlinux severitylow sprintbacklog labels

assigned to @ffauteux-chapleau

https://git.jami.net/savoirfairelinux/jami-client-qt/-/wikis/Changelog

Could this also help with https://github.com/flathub/net.jami.Jami/issues/86?

Cf. jami-daemon#973

assigned to @atraczyk

https://review.jami.net/c/jami-client-qt/+/28978

mentioned in commit b7fb63ae

added sprintin progress label and removed sprintbacklog label

There's no difference between the "nightly" and "beta" in the context of Jami. "Beta" is more accurate. It is unknown why "nightly" is used internally. Internally, "nightly" may be changed to "beta" in the future when the #1820 issue is addressed.

https://review.jami.net/c/jami-docs/+/30748