crypto: remove explicit qualifiers in Initialize

This commit removes the explicit namespace qualifiers in
Connection::Initialize, and SecureContext:Initialize which should not
necessary in a member function (using an unqualified name should resolve
by searching the class of the member function).

This is consistent with the other intialize functions in node_crypto
like Hmac::Initialize, Hash::Initialize, Sign::Initialize,
Verify::Initialize, DiffieHellman::Initialize, ECDH::Initialize,
and InitCrypto.

PR-URL: https://github.com/nodejs/node/pull/17490


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>