Support registering views

[matko]

Is your feature request related to a problem or challenge? Please describe what you are trying to do.
I am trying to create a view over a set of parquet files that I often need to query together in a particular way.
Datafusion supports views, essentially logical plans that are registered as a table (through ViewTable). Unfortunately, this functionality is not exposed in the python bindings.

Describe the solution you'd like
Expose ViewTable in the datafusion-python bindings, so that they can be created from a LogicalPlan and then registered with SessionContext.register_table.

Describe alternatives you've considered
There is also a DDL syntax for creating views. This works fine in many scenarios, but is less ideal in dynamic scenarios where it means having to compose a view as a string. This leads to all sorts of potential injection problems.

[kosiew]

take