Fix pathlen not copied in ASN1_OBJECT_dup and not marked set in X509_add_ext

[cconlon]

Description

This PR:

• Fixes wolfSSL_ASN1_OBJECT_dup() to duplicate the pathlen ASN1_INTEGER field, with cleanup on allocation failure.
• Fixes wolfSSL_X509_add_ext() to set pathLengthSet = 1 when adding a basic constraints extension that includes a path length.

Testing

Simple unit tests added. Originally caught when doing Java/JNI feature expansion work.

Checklist

• added tests
• updated/added doxygen
• updated appropriate READMEs
• Updated manual and documentation

[Copilot]

Pull request overview

Fixes missing propagation of basic-constraints path length metadata by (1) ensuring wolfSSL_ASN1_OBJECT_dup() duplicates the pathlen field and (2) ensuring wolfSSL_X509_add_ext() marks pathLengthSet when a path length is present.

Changes:

• Duplicate obj->pathlen in wolfSSL_ASN1_OBJECT_dup() with allocation-failure cleanup.
• Set x509->pathLengthSet = 1 when adding basic constraints with a path length.
• Add unit tests covering both behaviors.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 3 comments.

File	Description
tests/api/test_ossl_x509_ext.c	Adds assertions that pathLengthSet is set when basic constraints includes a path length.
tests/api/test_ossl_asn1.c	Adds tests verifying ASN1_OBJECT_dup copies (or preserves NULL) pathlen.
src/x509.c	Sets pathLengthSet when applying basic constraints with a path length.
src/ssl_asn1.c	Copies pathlen during ASN1 object duplication and guards follow-on duplication when allocation fails.

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[cconlon]

Retest this please Jenkins - timeout on PRB-fsanitize-addr-v3

[cconlon]

Currently failing on:

1. PRB-FIPS-windows-test-ACVP (Cannot open include file: 'BaseTsd.h': No such file or directory)
2. PRB-generic-config-parser (FAIL scripts/google.test)

2 looks like it will be fixed with #9944. 1 may be sporadic?