Custom authentication engine startup and shutdown process

During startup, OneSpan Authentication Server performs the following steps for each defined custom authentication engine:

1. Load the authentication engine library to the server process.
2. If step 1 succeeds, call the ikey_initialise() function of the authentication engine library.

3. If step 2 succeeds, register the authentication engine in the system.

   If step 2 fails, unload the authentication engine library from the server process.

During shutdown, OneSpan Authentication Server performs the following steps for each defined custom authentication engine:

1. Unregister the custom authentication engine from the system.
2. Call the ikey_terminate() function of the authentication engine library.
3. Unload the authentication engine library from the server process.