Detect failure from insufficient privileges in introspection (and migrate?)

Example from https://github.com/prisma/migrate/issues/647

run `npx prisma introspect` 

```
Introspecting based on datasource defined in prisma/schema.prisma …
Oops, an unexpected error occured!
[libs/sql-schema-describer/src/mysql.rs:156:53] table columns not found
```

The current error is not super helpful right now.