Dilithium: DER encoding fix

[SparkiDev]

Description

Underlying function SetAsymKeyDer() changed semantics.
Update tests to reflect new behaviour.

Testing

./configure '--disable-shared' '--enable-experimental' '--enable-dilithium'
/tests/unit.test -test_wc_dilithium_der

Checklist

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

[douzzer]

[pq-hybrid-all-rpk] [1 of 5] [6da66ad2cb]
    autogen.sh 6da66ad2cb...   real 0m17.303s  user 0m14.986s  sys 0m1.417s
    configure...   real 0m18.608s  user 0m7.122s  sys 0m13.333s
    build...   real 0m45.530s  user 2m55.472s  sys 0m12.640s
    check...   real 0m28.265s  user 0m19.363s  sys 0m11.498s
    pq-hybrid-all-rpk OK
[pq-hybrid-all-rpk-clang-tidy] [2 of 5] [6da66ad2cb]
    configure...   real 0m25.975s  user 0m11.654s  sys 0m16.079s
    build...   real 2m58.581s  user 21m1.475s  sys 0m29.704s
    check...   real 0m25.625s  user 0m20.192s  sys 0m11.569s
    pq-hybrid-all-rpk-clang-tidy OK
[pq-hybrid-all-rpk-sanitizer] [3 of 5] [6da66ad2cb]
    configure...   real 0m20.897s  user 0m8.453s  sys 0m14.266s
    build...   real 2m32.358s  user 9m59.204s  sys 0m19.575s
    check...   real 0m49.650s  user 0m51.352s  sys 0m22.327s
    pq-hybrid-all-rpk-sanitizer OK
[pq-hybrid-all-rpk-cppcheck] [4 of 5] [6da66ad2cb]
    configure...   real 0m17.781s  user 0m6.637s  sys 0m13.002s
    cppcheck...   real 2m27.081s  user 19m48.707s  sys 1m9.079s
    pq-hybrid-all-rpk-cppcheck OK
[pq-hybrid-all-rpk-valgrind-unittest] [5 of 5] [6da66ad2cb]
    configure...   real 0m19.239s  user 0m7.766s  sys 0m13.300s
    build...   real 0m56.471s  user 3m5.135s  sys 0m12.480s
    valgrind unit.test...   real 7m5.743s  user 6m58.542s  sys 0m1.273s
    pq-hybrid-all-rpk-valgrind-unittest OK
final tally: all 5 selected checks succeeded for 6da66ad2cb.