OS upgrade UX: prompt to create a toolbox for the current OS version

**Is your feature request related to a problem? Please describe.**
If a user upgrades the host, the default path is for them to stick with their toolboxes from the previous OS version. While this is good in some respects (it eases the upgrade experience and gives the user more flexibility), it also creates the issue of users lingering on old versions, when they would likely be having a better experience with the latest and greatest.

**Describe the solution you'd like**
A good solution might be to prompt the user to create a toolbox for the current OS version, either after upgrade or if no toolboxes for the current version are found.

**Describe alternatives you've considered**
The obvious alternative would be to prompt the user to upgrade their toolboxes themselves, but I'm guessing that's either a) not possible or b) not desirable.