sqlite: invalidate sessions when closing database

[trivikr]

Fixes: #64782

This change tracks Session wrappers instead of native handles and
deletes sessions through Session::Delete(). This marks each wrapper as
closed when its native handle is deleted. After the database is reopened,
using an old session now throws session is not open.

---

Assisted-by: codex:gpt-5.6-sol

[nodejs-github-bot]

Review requested:

• @nodejs/sqlite

[codecov]

Codecov Report

❌ Patch coverage is 62.50000% with 6 lines in your changes missing coverage. Please review.
✅ Project coverage is 90.16%. Comparing base (54a5095) to head (c51eb62).
⚠️ Report is 9 commits behind head on main.

Files with missing lines	Patch %	Lines
src/node_sqlite.cc	62.50%	3 Missing and 3 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #64783      +/-   ##
==========================================
+ Coverage   90.14%   90.16%   +0.02%     
==========================================
  Files         744      744              
  Lines      242518   242528      +10     
  Branches    45685    45693       +8     
==========================================
+ Hits       218611   218676      +65     
+ Misses      15396    15355      -41     
+ Partials     8511     8497      -14     

Files with missing lines	Coverage Δ
src/node_sqlite.h	80.64% <ø> (ø)
src/node_sqlite.cc	80.55% <62.50%> (-0.12%)	⬇️

... and 33 files with indirect coverage changes

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[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/75225/