Changed generation of RSA keys via CAE application

The generation of RSA private and public keys via CAE application has changed. The keys are required for creating a signed token to identify anonymous visitors. Before, a new key pair (signCookie.publicKey and signCookie.privateKey) was created and logged, if a value was missing or invalid. Now a new key pair can be generated via code or actuator, see documentation for details.

(CMS-22836)