Ad Reporting V2 Updates

[fivetran-sheringuyen]

Pull Request Are you a current Fivetran customer? Fivetran created

What change(s) does this PR introduce?

• Updates source models to include more potentially useful columns and respective definitions within src.yml and stg.yml.
• Added passthrough functionality for BASIC_AD pre-built report using facebook_ads__basic_ad_metrics variable.
• Updates is_most_recent_record logic to take in updated_time rather than _fivetran_synced for the following models:
  • stg_facebook_ads__campaign_history
  • stg_facebook_ads__ad_set_history
  • stg_facebook_ads__ad_history
• Model grain tests were added for better data integrity.
• Addition of identifier variables for each of the source tables to allow for further flexibility in source table direction within the dbt project.
• README updates for easier navigation and use of the package.

Did you update the CHANGELOG?

• [x] Yes

Does this PR introduce a breaking change?

• [x] Yes (please provide breaking change details below.)
• [ ] No (please provide an explanation as to how the change is non-breaking below.)

Did you update the dbt_project.yml files with the version upgrade (please leverage standard semantic versioning)? (In both your main project and integration_tests)

• [ ] Yes

Is this PR in response to a previously created Bug or Feature Request

• [ ] Yes, Issue/Feature [link bug/feature number here]
• [x] No

How did you test the PR changes?

• [x] CircleCi
• [x] Local (please provide additional testing details below)

Select which warehouse(s) were used to test the PR

• [x] BigQuery
• [x] Redshift
• [x] Snowflake
• [x] Postgres
• [x] Databricks
• [ ] Other (provide details below)

Provide an emoji that best describes your current mood

:dancer: **Feedback** We are so excited you decided to contribute to the Fivetran community dbt package! We continue to work to improve the packages and would greatly appreciate your [feedback](https://www.surveymonkey.com/r/DQ7K7WW) on our existing dbt packages or what you'd like to see next.

[fivetran-sheringuyen]

Howdy @fivetran-joemarkiewicz ! Just updated with the fixes and resolved the fixed convos. Let me know if there's anything else you want to discuss!

[fivetran-sheringuyen]

Running comments before merge:

• Add not_null testing in stg tests
• Update macros columns to be included and add passthrough logic in CTEs for staging models