[CT-3527] [implementation] extend access and groups to exposures & source

[graciegoheen]

Housekeeping

• I am a maintainer of dbt-core

Short description

From the discussion here...

We should extend group configurations to all resource types. The current outstanding ones are sources and exposures:

• exposures should be able to reference models within the same group
• sources should be able to be private to a given group

We should also enable sources to configure access to private or protected (default). We should not allow folks to set access to public for sources.

Acceptance criteria

• you can set group config for an exposure
• you can set group config for a source
• you can set access to private or protected (default) for a source
• you can not set access for an exposure (they are inherently public)

As described here, referencing a resource outside of its supported access should raise an error (but otherwise should not).

Impact to Other Teams

none

Will backports be required?

none

Context

Notes from technical refinement:

• would allow folks to set this for the source, and also for a specific table within a source
• it's a config (enabled is the only one right now https://docs.getdbt.com/reference/source-configs), may be more complicated