Add "example" capability to pyspark based data schemas

[pascalwhoop]

Is your feature request related to a problem? Please describe.

• We use spark for all our heavy data wrangling
• we want to use pandera to generate test / fake data

Describe the solution you'd like
an ability to use .example(size=20) also with pyspark based schemas

Describe alternatives you've considered

• convert pyspark schema somehow automatically to a pandas one and then use example
• could not figure out if there is a way to do so
• ideally we'd also define the schema in a "agnostic" format (e.g. protofbuf / custom DSL / yaml / pydantic based) and derive the pyspark / pandas schema code from this