[POC] Unit Testing

[MichelleArk]

resolves #
docs dbt-labs/docs.getdbt.com/#

Problem

Solution

Checklist

• I have read the contributing guide and understand what's expected of me
• I have run this code in development and it appears to resolve the stated issue
• This PR includes tests, or tests are not required/relevant for this PR
• This PR has no interface changes (e.g. macros, cli, logs, json artifacts, config files, adapter interface, etc) or this PR has already received feedback and approval from Product or DX

[github-actions]

Thank you for your pull request! We could not find a changelog entry for this change. For details on how to document a change, see the contributing guide.

[codecov]

Codecov Report

Merging #8188 (88eb4d6) into main (eeb0570) will decrease coverage by 3.66%.
The diff coverage is 48.10%.

@@            Coverage Diff             @@
##             main    #8188      +/-   ##
==========================================
- Coverage   86.17%   82.52%   -3.66%     
==========================================
  Files         174      176       +2     
  Lines       25498    25832     +334     
==========================================
- Hits        21974    21318     -656     
- Misses       3524     4514     +990     

Impacted Files	Coverage Δ
core/dbt/contracts/graph/model_config.py	89.92% <ø> (-3.88%)	⬇️
core/dbt/parser/unit_tests.py	20.00% <20.00%> (ø)
core/dbt/cli/requires.py	89.03% <30.76%> (-5.34%)	⬇️
core/dbt/task/unit_test.py	42.55% <42.55%> (ø)
core/dbt/clients/jinja.py	87.11% <42.85%> (-1.75%)	⬇️
core/dbt/context/providers.py	86.51% <51.21%> (-2.14%)	⬇️
core/dbt/parser/schemas.py	92.53% <66.66%> (-0.22%)	⬇️
core/dbt/compilation.py	95.10% <75.00%> (-1.03%)	⬇️
core/dbt/cli/main.py	98.13% <89.18%> (-0.55%)	⬇️
core/dbt/contracts/graph/nodes.py	90.17% <93.75%> (-3.17%)	⬇️
... and 4 more

... and 58 files with indirect coverage changes