Integration Test Suite Cleanup & Abstraction

### What

Child of #49

**Description:**
Clean up and decouple S-CORE's ITF test framework from all legacy SoftHSM-specific hardcodings across init_pkcs11_token.cpp, integration_test.py, and score_demo.cpp (including variables,and prints). Use Bazel select() blocks in S-CORE's BUILD targets to dynamically
package and upload only S-CORE's active backend provider library.

This resolves the discussion here https://github.com/eclipse-score/inc_security_crypto/pull/49#:~:text=Reply...-,score/tests/integration_tests/init_pkcs11_token.cpp,1,-Reply...

### Acceptance Criteria (DoD)

All SoftHSM-specific hardcodings (prints, paths, variables) are abstracted, enabling both the legacy SoftHSM and the secure Rust backends to compile and pass S-CORE's test suite runs

### How

_No response_

Start by reading init_pkcs11_token.cpp, integration_test.py, score_demo.cpp, and the relevant S-CORE BUILD targets, then review the discussion linked from #49. Run the integration test suite for the existing backend configurations. Done means both the legacy SoftHSM and secure Rust backends compile and pass, with backend-specific paths, variables, prints, packaging, and uploads no longer hardcoded.

Written by the indexing model from the issue text.