## Changes
1. Change the **default-python** bundle template to set
`data_security_mode` of a cluster to SINGLE_USER
2. Change the **experimental-jobs-as-code** bundle template to set
`data_security_mode` of a cluster to SINGLE_USER
## Why
Explicitly adding this field saves experienced users from confusion onto
what security mode is applied to the cluster
## Tests
Changed existing unit and integration tests to pass with this change
## Changes
Add experimental-jobs-as-code template allowing defining jobs using
Python instead of YAML through the `databricks-bundles` PyPI package.
## Tests
Manually and acceptance tests.