PageView Demo requires more configuration properties to be used within secure environment

[kamir]

Currently, only the two properties:

• bootstrapServers
• schemaRegistryUrl
  are configurable via java application arguments.

It would be nice, if a properties file could be used to configure the consumer / producer of the demo applications.

[kamir]

Proposed solution:

Option A
Adding a third argument.
The string represents the path/filename of a properties file with all relevant configuration parameters.
In case it is not provided, demo works as until now. If it is provided,
the values in the properties file will overwrite the first two arguments.

This looks like a good short term solution.

Option B
Implement proper CLI argument handling via commons-cli.
If a generic component would be created, it could be reused in all examples.

This needs some more work, but would contribute to a better user experience.