Fix provider cmd test

[aidangarske]

Fix wolfProvider Command-Line Tests for Provider Switching

This PR fixes issues with provider switching in command-line tests and adds support for system/Debian package installations. Changes where supposed to be fixed in #324 still running into yocto issues and issues in nightly debian pacakge creation here

Changes:

• Fixed provider switching logic (cmd-test-common.sh):

  • Removed early return 0 statements that disabled provider switching functions
  • Properly handle replace-default mode (no switching needed, just verify wolfProvider is default)
  • Fixed normal mode switching to correctly set OPENSSL_CONF and OPENSSL_MODULES
  • Added system/Debian package installation detection for finding provider library paths (/usr/lib/*/ossl-modules/)
  • Improved error messages and path detection logic

• Enhanced replace-default mode detection (env-setup, utils-general.sh):

  • Auto-detect replace-default mode from OpenSSL version string (checks for "replace-default")
  • In replace-default mode, unset OPENSSL_CONF and OPENSSL_MODULES to use native default provider behavior
  • Updated is_wp_default detection to correctly identify wolfProvider as default in replace-default mode

• Improved system installation support:

  • Detect Debian package installations when OPENSSL_BIN is /usr/bin/openssl
  • Use system paths (/usr/lib/*/ossl-modules/ and /etc/ssl/openssl.cnf.d/wolfprovider.conf)
  • Fallback to local build paths if system paths are not found

• Updated documentation (do-cmd-tests.sh):

  • Clarified environment variable usage in help text
  • Noted that modes are auto-detected (no flags needed)

Testing:

• Works correctly in normal mode (can switch between OpenSSL default and libwolfprov)
• Works correctly in replace-default mode (verifies wolfProvider is default, no switching)
• Supports both local builds and system/Debian package installations
• tested here https://cloud.wolfssl-test.com/jenkins/job/wolfProvider/job/debian-packages/