Update `CassandraAutoConfiguration` so that properties in a
`spring.data.cassandra.config` file can override the default values
defined in `CassandraProperties`.
This commit changes two things:
1. Any primitive on `CassandraProperties` are replaced with object values.
This allows distinguishing between defaults values and no-values. Then
CassandraAutoConfiguration.mapConfig() can use whenNonNull() predicate
to ignore those.
2. `CassandraProperties` no longer populate default values on any
property. With that, the defaults can be applied on top of the file
spring.data.cassandra.config; i.e. the config file have higher
precedence than the defaults, but lower that any spring.data.cassandra.*
property.
See gh-31238
1c7d99890e