Add metadata extraction pivot

[LewisDavies]

Are you a current Fivetran customer?

Lewis Davies, Prisma

What change(s) does this PR introduce?

My Stripe data has metadata columns in the card and invoice_line_items. I've added the metadata extraction macro to these models.

Did you update the CHANGELOG?

• [ ] Yes

Does this PR introduce a breaking change?

• [ ] Yes (please provide breaking change details below.)
• [x] 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?

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

I added the relevant variables to my project and built the changed models locally. In my Stripe data card didn't have any values in metadata, but I was able to extract successfully extract values from invoice_line_item.

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

• [ ] BigQuery
• [ ] Redshift
• [x] Snowflake
• [ ] Postgres
• [ ] 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.

[LewisDavies]

FYI @fivetran-joemarkiewicz

[fivetran-joemarkiewicz]

Hi @LewisDavies thanks for bumping this! Our new sprint just started yesterday. I will review this as part of it 😄