feat: add support for distributed incremental microbatches

[canbekley]

Adds support for microbatch distributed incremental materialization, by adding a new model config is_distributed. Distributed models that run in microbatches would need to be created as following:

{{
    config(
        materialized='incremental',
        is_distributed=True,
        incremental_strategy='microbatch',
        ...
    )
}}
...

related issue: #439

[Copilot]

Pull Request Overview

This PR adds support for distributed incremental microbatches by introducing a new model config is_distributed and updating the underlying adapter logic accordingly.

• Updates integration tests to include distributed and non-distributed cases
• Modifies ClickHouseRelation.get_on_cluster and ClickHouseConnectionManager methods to account for the new is_distributed flag
• Adds a get_materialization function in the ClickHouse adapter to properly alias materialization types for distributed models

Reviewed Changes

Copilot reviewed 4 out of 6 changed files in this pull request and generated 2 comments.

File	Description
tests/integration/adapter/incremental/test_incremental_microbatch.py	Updates tests to pass is_distributed values and use dynamic materialized settings for both distributed and non-distributed scenarios
dbt/adapters/clickhouse/relation.py	Updates get_on_cluster signature and usage to include the is_distributed flag derived from model configs
dbt/adapters/clickhouse/impl.py	Propagates the is_distributed flag in the should_on_cluster method
dbt/adapters/clickhouse/init.py	Introduces get_materialization to transform materialized and is_distributed settings for compatibility

Files not reviewed (2)

• dbt/include/clickhouse/macros/adapters/relation.sql: Language not supported
• dbt/include/clickhouse/macros/materializations/incremental/distributed_incremental.sql: Language not supported

[Copilot]

The is_distributed parameter is provided as a string ('False' or 'True') in this test, but the adapter functions expect a boolean value. Consider converting the string to a boolean to avoid misinterpretation of truthy values.

Suggested change

	"microbatch_model.sql": _microbatch_model_sql % "False", # `is_distributed` param
	"microbatch_model.sql": _microbatch_model_sql % False, # `is_distributed` param

[Copilot]

The value for is_distributed may be passed as a string instead of a boolean, which could lead to unintended behavior in get_on_cluster. Consider adding an explicit conversion to boolean.

Suggested change

	is_distributed = relation_config.config.get('extra', {}).get('is_distributed')
	engine = relation_config.config.get('engine') or ''
	is_distributed = relation_config.config.get('extra', {}).get('is_distributed')
	# Ensure is_distributed is a boolean
	is_distributed = str(is_distributed).lower() == "true" if is_distributed is not None else False