Remove the extern const crypto profile

Issue from discussion #612 (closed)
File: lib_itf/sopc_crypto_profiles_lib_itf.h

Remove the extern const variable sopc_g_cp* and declare an access function that takes the security policy URI as input argument and returns the corresponding profile. The declaration should be as follows:

const SOPC_CryptoProfile* SOPC_CryptoProfile_LibProfile_Get(const char* uri)

The field profile of the structure SOPC_SecurityPolicy_Config shall be replaced by a function pointer to the access function (file: src/Common/crypto/sopc_crypto_profiles.h). Each instance of SOPC_SecurityPolicy_Config from file src/Common/crypto/sopc_crypto_profiles.c shall take the access address.