v1.3.0 regression: Restoring snapshots from previous versions

[rfay]

Describe the bug

• At one point it was easily possible to restore snapshots by just changing the dbcontainer in config.yaml per https://ddev.readthedocs.io/en/latest/users/troubleshooting/#old-snapshot

However, I seem to have increased the error-checking in the snapshot code in ddev itself and it now prevents that. So you still get $ ddev restore-snapshot umami_maria_10_1 Failed to restore snapshot umami_maria_10_1 for project d8git: snapshot db_snapshots/umami_maria_10_1 is not compatible with this version of ddev and mariadb. Please use the instructions at https://ddev.readthedocs.io/en/latest/users/troubleshooting/#old-snapshot for a workaround to restore it but unfortunately that workaround doesn't work.

• An additional step was required anyway. You had to ddev rm -RO before starting up, because the v1.2.0 container was unable to function with the v1.3.0 database, so came up broken.

[rfay]

I think this can be fixed by changing https://github.com/drud/ddev/blob/c9e3cb59ca1d56f12b5c91eac464f2bcc0bdd413/pkg/ddevapp/ddevapp.go#L909-L911
app.Exec("db", "bash", "-c", "mysql --database=mysql -e 'DROP DATABASE IF EXISTS db; CREATE DATABASE db;' && cat /db/*.*sql | mysql db")
to add an app.Exec('db', 'bash', '-c', 'mariabackup --version | grep 10.2') or something like that.