Bug in SLHDSA KeyPairGenerator when algorithm name is already parameterized

[Ali-Sayedsalehi]

When using SLHDSA algorithm, If the algorithm name is already parameterized (e.g. SLH-DSA-SHA2-128S) and initialization is skipped, we get this error:

Cannot invoke "org.openssl.jostle.jcajce.spec.OSSLKeyType.getKsType()" because "this.keyType" is null
java.lang.NullPointerException: Cannot invoke "org.openssl.jostle.jcajce.spec.OSSLKeyType.getKsType()" because "this.keyType" is null
	at org.openssl.jostle.jcajce.provider.slhdsa.SLHDSAKeyPairGenerator.generateKeyPair(SLHDSAKeyPairGenerator.java:99)
	at org.openssl.jostle.test.slhdsa.SLHDSATest.testSignVerifyWithContextAndReuse(SLHDSATest.java:303)

To reproduce:

KeyPairGenerator keyGen = KeyPairGenerator.getInstance("SLH-DSA-SHA2-128s", JostleProvider.PROVIDER_NAME);

// we should skip this step
// keyGen.initialize(SLHDSAParameterSpec.slh_dsa_sha2_128s);

KeyPair keyPair = keyGen.generateKeyPair();

The fix would be to add this section:

if (forcedType != OSSLKeyType.NONE)
{
    keyType = forcedType;
}

to the constructor:

openssl-jostle/jostle/src/main/java/org/openssl/jostle/jcajce/provider/slhdsa/SLHDSAKeyPairGenerator.java

Line 55 in 7ddd316

public SLHDSAKeyPairGenerator(Object algorithm)