Support exposures

[joellabes]

Exposures are not currently persisted to the Fusion-generated manifest, and their contents are not validated (e.g. you could include a non-existent ref in your YAML without any errors).

This will include:

• persisting exposures to the manifest
• including exposures in the graph context variable
• validating properties (e.g. that your refs exist)
• The exposure: selection method
• For eligible dbt Platform customers, restoring support for detecting and triggering exposures automatically
• The following exposure-specific properties:
  • name
  • label
  • depends_on
  • owner
  • maturity (with added support for arbitrary options)
  • url
  • type (with added support for arbitrary options)

[jtcohen6]

Initial implementation in da00b92 !

• yaml-defined exposures: parsing → manifest nodes
• validation for exposure names (cannot contain unsupported/special characters)

Still to come:

• exposure: selector method [FEAT] exposure:: selector method for exposures #633
• auto/active exposures (dbt platform)

[jtcohen6]

Closing as implemented - I opened #704 to more narrowly target follow-up parity work for auto + active exposures (for eligible dbt Platform customers)

[haritamar]

@jtcohen6 @b-per - from what I can tell the exposures key in the graph is still empty in the most recent version, was it definitely fixed?