Address CodeQL issues

[David-Engel]

This pull request mainly improves code clarity and static analysis by adding detailed comments to justify reinterpret_cast usage when handling UTF-16 buffers from ODBC, and it also adjusts the configuration for CodeQL analysis and test certificate validity. The most important changes are grouped below:

Static Analysis and Documentation Improvements:

• Added detailed comments and CodeQL annotations to explain the use of reinterpret_cast for buffers containing UTF-16 data from ODBC output parameters in core_stmt.cpp, core_stream.cpp, and core_util.cpp. These comments clarify that the cast is safe due to ODBC guarantees and are annotated for CodeQL suppression [1]], [2]], [3]]).

CodeQL Configuration:

• Updated CodeQL.yml to exclude all external PHP SDK source code from analysis, but explicitly include only the sqlsrv and pdo_sqlsrv source files within the PHP SDK ([CodeQL.ymlR1-R10]).

C++ Lint Fix

• Fix lint errors in core_sqlsrv.h: style: Virtual function 'release_data' is called from destructor 'sqlsrv_param()' at line 1465 [and 1542]. Dynamic binding is not used.

Test Improvements:

• Reduced the validity period of generated self-signed certificates in mock_tds_server.py from 365 days to 30 days to improve test hygiene ([test/tools/mock_tds_server.pyL1344-R1344]) and also avoid CodeQL analysis thinking it was "year math without considering leap years".

[codecov]

Codecov Report

❌ Patch coverage is 33.33333% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 85.72%. Comparing base (15d7cfd) to head (c5561b6).

Files with missing lines	Patch %	Lines
source/shared/core_sqlsrv.h	0.00%	2 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##              dev    #1615   +/-   ##
=======================================
  Coverage   85.72%   85.72%           
=======================================
  Files          23       23           
  Lines        7210     7210           
=======================================
  Hits         6181     6181           
  Misses       1029     1029           

Files with missing lines	Coverage Δ
source/shared/core_stmt.cpp	93.51% <ø> (ø)
source/shared/core_stream.cpp	86.73% <ø> (ø)
source/shared/core_util.cpp	89.51% <100.00%> (ø)
source/shared/core_sqlsrv.h	89.94% <0.00%> (ø)

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