Refactor macro contexts.

[peterallenwebb]

resolves #9422

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
• This PR includes type annotations for new and modified functions

[codecov]

Codecov Report

Attention: 2 lines in your changes are missing coverage. Please review.

Comparison is base (c547aac) 86.98% compared to head (d8bcfd4) 86.98%.

Files	Patch %	Lines
core/dbt/contracts/graph/manifest.py	95.55%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #9423      +/-   ##
==========================================
- Coverage   86.98%   86.98%   -0.01%     
==========================================
  Files         187      187              
  Lines       24971    25014      +43     
==========================================
+ Hits        21722    21758      +36     
- Misses       3249     3256       +7     

Flag	Coverage Δ
integration	84.36% <96.22%> (-0.01%)	⬇️
unit	63.31% <96.22%> (+0.05%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.