Bootstrap: core should be validated after restart

[Williangalvani]

validation can be done by checking the versionchooser /version/current endpoint. If versionchooser is broken, we should revert to the previous version.

[patrickelectric]

We should have a frontend interface and a /recovery endpoint for the version chooser frontend

[Williangalvani]

done in #729

We should have a frontend interface and a /recovery endpoint for the version chooser frontend

should we track this in another issue?