fun loadCertificateAndKey(keyStore: KeyStore, keyPassword: String, alias: String): CACertAndKeyHelper method to load a Certificate and KeyPair from their KeyStore. The access details should match those of the createCAKeyStoreAndTrustStore call used to manufacture the keys.
keyStore - Source KeyStore to look in for the datakeyPassword - The password for the PrivateKey (not the store access password)alias - The name to search for the data. Typically if generated with the methods here this will be one of
CERT_PRIVATE_KEY_ALIAS, ROOT_CA_CERT_PRIVATE_KEY_ALIAS, INTERMEDIATE_CA_PRIVATE_KEY_ALIAS defined above