Feature: Display external tables details

[portalhacker]

resolves #572

Description

Add an optional new container to the table-details template with a clickable link.

Then hydrate it based on the keys and values found under the source external key for dbt-labs/dbt_external_tables.

This was tested for 2 types of external tables with BigQuery:

• Google Cloud Storage
• Google Sheets

It should work in every database and external table types.

Here is an example of the output:

Checklist

• I have read the contributing guide and understand what's expected of me
• I have signed the CLA
• I have run this code in development and it appears to resolve the stated issue
• I have opened an issue to add/update docs, or docs changes are not required/relevant for this PR
• I have run changie new to create a changelog entry

[portalhacker]

Hi @dbt-labs/core-team,
Do you have estimated delays for PR reviews?

@emmyoop I see you you reviewed a recent PR and I am not sure the CODEOWNERS mention works properly.

[portalhacker]

Hi @ddk-dbt
Just trying to find someone to review this PR 😉