Fix pre-reset callback for sessions that are not logged on

[6democratickim9]

Summary

Call ApplicationExtended.onBeforeSessionReset() from Session.reset()
even when the session is disconnected or not yet logged on.

The callback runs before the message store is reset. Logged-on sessions
retain the existing Logout handshake.

Fixes #327

Tests

• Added coverage for disconnected, connected-but-not-logged-on,
  and logged-on sessions.
• Verified callback count, store contents before reset, and reset completion.
• Before the fix: 2 of the 3 regression tests failed.
• After the fix: all 81 SessionTest tests passed.
• Full Maven clean install passed on Java 21 with
  skipBundlePlugin,minimal-fix-latest and Javadoc generation skipped.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 70.81%. Comparing base (149869e) to head (3244c81).

Additional details and impacted files

@@             Coverage Diff              @@
##             master    #1346      +/-   ##
============================================
+ Coverage     70.79%   70.81%   +0.02%     
  Complexity     2270     2270              
============================================
  Files           161      161              
  Lines          9077     9077              
  Branches       1192     1192              
============================================
+ Hits           6426     6428       +2     
+ Misses         2198     2196       -2     
  Partials        453      453              

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.