Upgrade fails

[Kaik]

Upgrade fails and these are issues to solve:

• Prefix for old tables - upgrade fails when $this->container->getParameter("prefix") does not exists.
• line 308 translations error add ['%s' => $prefix]
• line 313 removing hooks (it might be not needed)
• next lines ranks
• PDO Exception about serializing and unserializing object $this->schema->update($this->entities)

The last one is a blocker and I'm currently investigating this.

[Kaik]

I'm really considering upgrade using import.
So old tables are marked with ```backup_`` prefix and new ones are created then everything is imported.
Need to think about this.

[Kaik]

Done