[Feature] Localhost Livy session support

[mdrakiburrahman]

Is this your first time submitting a feature request?

• I have searched the existing issues, and I could not find an existing issue for this feature
• I am requesting a straightforward extension of existing dbt functionality, rather than a Big Idea better suited to a discussion

Describe the feature

Fabric Spark runs the same routes as OSS livy.

Having local livy support significantly increases testability of this adapter since one can test E2E on smaller sample datasets locally, and also regression test in CI pipelines.

Describe alternatives you've considered

Using Fabric for all dev/test, but this isn't feasible for CI.

Who will this benefit?

Any engineering focused users of this adapter.

Are you interested in contributing this feature?

Yes

Anything else?

See draft PR where this works by using a livy_mode: local/fabric

#56

[mdrakiburrahman]

Example of this using local Livy: