[IMP] run: background-load second database from template while run

[lse-odoo]

Description

Before this commit:
Restoring a database template can be a long process depending on the database size. In upgrade/maintenance, it can be needed that we re-run the same database multiple times to test upgrade scripts. As such, we generally interupt the running odoo-bin process then launch again the commdand:
odev run <db> -t <db template>

After this commit:
The idea is to use the time while we are testing on the running database to restore another database of the same template then "swap" them when the first one is interupted in order to be available to run as soon as possible.
This process goes on as long as odev itself is interupted with Ctrl+C

Compliance

• I have read the contribution guide
• I made sure the documentation is up-to-date both in doctrings and the docs directory
• I have added or modified unit tests where necessary
• I have added new libraries to the requirements.txt file, if any
• I have incremented the version number according the versioning guide
• The PR contains my changes only and no other external commit