Feature/python model beta

[ueshin]

Description

Ports the changes for python model v1 from dbt-spark but use APIs below instead.

• Create an execution context
• Run a command
• Get information about a command
  • loop until the command ends
• Delete an execution context

[ueshin]

This is now based on #148. Please take a look at it first.

[zhengruifeng]

https://github.com/databricks/jaffle_shop/pull/1/files#r969108078 please take a look at this, it seems that python model cann't work with view materialization

[ueshin]

it seems that python model cann't work with view materialization

Yes, so far it's a limitation of python model. https://docs.getdbt.com/docs/building-a-dbt-project/building-models/python-models#materializations

[zhengruifeng]

@ueshin Since it's a known issue, then I think this PR works well. I don't find other issue right now

[ueshin]

Thanks! merging.