Add more information to unhandled incoming request logging

[misscoded]

Summary

Partially addresses #1138.

This PR adds more information about incoming unhandled requests, specifically the method and endpoint (similar to the information offered when errors are thrown). This should save developers time when debugging cases where there's a mismatch in endpoints compared to the Request URLs in the app configuration.

Previous: [INFO] An unhandled request was ignored
With change: [INFO] Unhandled HTTP request (POST) made to /slack/bad-endpoint

Requirements (place an x in each [ ])

• I've read and understood the Contributing Guidelines and have done my best effort to follow them.
• I've read and agree to the Code of Conduct.

[codecov]

Codecov Report

Merging #1143 (c06e138) into main (01ad01a) will not change coverage.
The diff coverage is 0.00%.

@@           Coverage Diff           @@
##             main    #1143   +/-   ##
=======================================
  Coverage   71.71%   71.71%           
=======================================
  Files          15       15           
  Lines        1354     1354           
  Branches      402      402           
=======================================
  Hits          971      971           
  Misses        312      312           
  Partials       71       71           

Impacted Files	Coverage Δ
src/receivers/HTTPReceiver.ts	37.12% <0.00%> (ø)

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[seratch]

Nice improvement as the first step!

To make the logging by the server consistent, we may want to add the method/path information to the error logging in L242 too.