fix: add missing @digitalbazaar/ezcap-express to dependencies

[bparth24]

This PR addresses #66.

The ezcap-express package is imported in lib/middleware.js but was not
declared in package.json dependencies, causing ERR_MODULE_NOT_FOUND
errors at runtime.

Ready for review - @dlongley @davidlehn @BigBlueHat @mandyvenables @gannan08 @tminard @jameseaster

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.78%. Comparing base (76cf8fb) to head (89a4293).

Additional details and impacted files

@@           Coverage Diff           @@
##             main      #67   +/-   ##
=======================================
  Coverage   90.78%   90.78%           
=======================================
  Files          13       13           
  Lines        1834     1834           
=======================================
  Hits         1665     1665           
  Misses        169      169           

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[davidlehn]

Cleaned up some more missing and unused deps. npm-check ftw.