chore: refactor watch processor test to reduce redundancy

[tamirazrab]

Description

Resolve max-statements warning in src/lib/processors/watch-processor.test.ts
...

End to End Test:
(See Pepr Excellent Examples)

Related Issue

Fixes #1696

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Other (security config, docs update, etc)

Checklist before merging

• Unit, Journey, E2E Tests, docs, adr added or updated as needed
• Contributor Guide Steps followed

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 82.11%. Comparing base (517bbd6) to head (38d8821).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1763   +/-   ##
=======================================
  Coverage   82.11%   82.11%           
=======================================
  Files          52       52           
  Lines        2214     2214           
  Branches      470      469    -1     
=======================================
  Hits         1818     1818           
- Misses        367      394   +27     
+ Partials       29        2   -27     

see 7 files with indirect coverage changes

[samayer12]

@tamirazrab I took at look at the test refactor and noticed there was an issue with resetting mocks between assertions. I reintroduced the manual mock-resets to get the tests to pass. As a follow-on item, we should consider the use of it.each() for the capabilities that are tested and more generally examine how we're using mocks in the test suite.

[samayer12]

Improving the test quality here can take multiple PRs, which is okay. This PR extracts the repeated assertions into a helper function used by a test.