Fix: Support individual query tag configuration for Seeds and Snapshots

[anthu]

resolves #20

Description

This Pull Request wraps the default materialisations of Seed and Snapshot with query tags.

Configuration examples

Configuration is equal to other materialisations:

Snapshots

snapshots/snip.sql

{% snapshot snip %}
{{
  config(
    target_database='db',
    target_schema='snapshots',
    unique_key='id',
    strategy='check',
    check_cols=['col_a'],
    query_tag='SNAPSHOT'
  )
}}

select * from {{ source('db', 'table') }}
{% endsnapshot %}

(Taken from issue)

Seeds

dbt_project.yml

seeds:
  jaffle_shop:
    +query_tag: 'dbt_jaffle_seeding'

---

seeds/marketing/properties.yml

version: 2

seeds:
  - name: utm_parameters
    config:
      schema: seed_data
      query_tag: 'dbt_utm_seeding'

Todo

• I have a test in mind:

1. Run Snapshot with Query Tag
2. Validate queries have been executed using the query_tag

select *
from table(information_schema.query_history_by_user())
where QUERY_TAG <> '';

(3. Query tag should be reset)

• CHANGELOG.md incoming

Checklist

• I have signed the CLA
• I have run this code in development and it appears to resolve the stated issue
• This PR includes tests, or tests are not required/relevant for this PR
• I have updated the CHANGELOG.md and added information about my change to the "dbt-snowflake next" section.

[anthu]

Ready for Review

[jtcohen6]

Closing and re-opening to trigger adapter integration tests, since I've added ok to test label

Edit: There are some unrelated test failures, related to recent changes to dbt-core. We'll work to get those sorted shortly

[jtcohen6]

@anthu This looks great — cleverly done, and nice tests to boot. Thanks for the contribution!