Force geopackage migration on upgrade to 300

[margrietpalm]

Upgrading from spatialite 3 to 4 happens after all migration steps are completed. This is necessary because the steps for this upgrade require the sqlites to match the model. Unfortunately, this requires that this upgrade remains working after every migration. To prevent this issue from continuing into schema 300 the following is proposed:

1. Migrate to schema 300
2. Convert to geopackage
3. Migrate to requested version (if > 300)

This has the following advantages

• Migrations after 300 do not need to be compatible with the spatialite upgrade
• Migrations after 300 do not need to support spatialite

Note that this does require the geopackage conversion to work without the matching ORM for the schematisation.

Add some checks in the upgrade function:

• Upgrading to version < 230: input must be spatialite
• Upgrading to version > 300: input must be geopackage