Add EventMonitor Test Class, Migrate Example Test

[peterallenwebb]

Resolves CORE-318

Problem

There was no simple/consistent way to ensure that dbt fired expected events under test.

Solution

Add a new EventMonitor class that can be handed to dbtRunner as an event callback. It takes a list of expected events and can be used to assert that they all fired.

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 or 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

All modified and coverable lines are covered by tests ✅

Project coverage is 88.79%. Comparing base (79ad0a3) to head (7b6013d).
Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #10481      +/-   ##
==========================================
- Coverage   88.85%   88.79%   -0.07%     
==========================================
  Files         180      180              
  Lines       22573    22573              
==========================================
- Hits        20058    20043      -15     
- Misses       2515     2530      +15     

Flag	Coverage Δ
integration	86.00% <ø> (-0.14%)	⬇️
unit	62.22% <ø> (ø)

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

Components	Coverage Δ
Unit Tests	62.22% <ø> (ø)
Integration Tests	86.00% <ø> (-0.14%)	⬇️

[QMalcolm]

@peterallenwebb Are we still figuring out how we want to move on this, or have we decided in favor of the existing EventCatcher class with the improvements made to it in #10482 and can now close this?

[peterallenwebb]

@QMalcolm I've decided to shelve this for now. Closing.