Update code should be more robust

[JeffreyDevloo]

Problem description

The current update code will stop if an exception is raised anywhere in between updating from the last supported version to the newest one.
For instance, updating from 1 to 6 and the code fails on changes for update 2: the environment won't be able to handle update 6.

[kvanhijf]

We should introduce something similar to what we have in the framework code, out-of-band migrations.
These are pieces of code which can be executed after the update and which won't have any impact on the update itself.
In the framework we use celerybeat for this purpose. What could be used for this in the ASD manager?