Livy connection support for Spark SQL models

[mukeshkumarkulmi]

resolves #483

Problem

Implemented Livy method to connect Livy server to submit Spark SQL through dbt-spark adapter and read results.

Solution

Use below in profile.yml

project:
target: dev
outputs:
 dev:
  type: spark_livy
  method: livy
  schema: schema
  host: Livy_server_url
  user: username
  password: password

[github-actions]

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