Log Analytics DataSource lacks proper definitions

Currently, different data sources' property are represented as plain JSON. It is non-trivial for the developer to digest the corresponding SDK, i.e., developer has to figure out the correct JSON format and define the model on their own.
It would be great if the swagger could define the "discriminator" for log analytics data sources.

Locate the Log Analytics data source definitions in the repository and inspect how their properties are currently represented in the API specification. Compare the available schemas with the desired OpenAPI discriminator behavior; done means developers can identify and use typed data-source definitions instead of interpreting plain JSON themselves.

Written by the indexing model from the issue text.