cubicweb #744389 db-restore: propose a dump before restoring [rejected]

Use case: user can use a wrong instance name or want to restore the dump later. Proposition: propose a db-dump first as first action which is to delete the database for now.

It can appear redundant but we could prevent some eventual grave production issue here.

priorityminor
typeenhancement
done in<not specified>
load0.000
load left0.000
closed by<not specified>