✨ Add app data + allow app and request data in unit tests

[jankoenig]

Proposed Changes

As suggested by @rmtuckerphx, you can now use testSuite.$data to write into the jovo.$data object for request data.

Types of Changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• My code follows the code style of this project
• My change requires a change to the documentation
• I have updated the documentation accordingly
• I have added tests to cover my changes
• All new and existing tests passed