Improve middleware test coverage

[thostetler]

Adds lots of middleware tests
Brings some mock-server based e2e tests back in so we can simplify a CI setup

[codecov]

Codecov Report

❌ Patch coverage is 83.67347% with 8 lines in your changes missing coverage. Please review.
✅ Project coverage is 72.3%. Comparing base (a4885b7) to head (77ddf63).
⚠️ Report is 2 commits behind head on master.

Files with missing lines	Patch %	Lines
src/middlewares/initSession.ts	64.3%	4 Missing and 1 partial ⚠️
src/middlewares/verifyMiddleware.ts	88.9%	3 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff            @@
##           master    #737     +/-   ##
========================================
+ Coverage    69.7%   72.3%   +2.7%     
========================================
  Files         221     221             
  Lines       24764   24803     +39     
  Branches     1342    1463    +121     
========================================
+ Hits        17253   17929    +676     
+ Misses       7470    6833    -637     
  Partials       41      41             

Files with missing lines	Coverage Δ
src/logger.ts	66.7% <100.0%> (+1.9%)	⬆️
src/middlewares/botCheck.ts	100.0% <100.0%> (+68.2%)	⬆️
src/mocks/handlers.ts	100.0% <100.0%> (ø)
src/middlewares/verifyMiddleware.ts	91.9% <88.9%> (+76.4%)	⬆️
src/middlewares/initSession.ts	90.7% <64.3%> (+59.8%)	⬆️

... and 6 files with indirect coverage changes

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