Move NCP related function into a seperate file and add unit tests

Move NCP related function into a seperate file and add unit tests

This allows unit test the NCP functions. The ssl.c file has too
many dependencies to make unit testing of it viable.

Patch V2: Removing the include "ssl_ncp.h" from options.c for V2 of
          implement dynamic NCP forces a new version of this patch to
          add the #include in this patch. Merge VS studio file changes
          for ssl_ncp.[ch] into this patch

Patch V3: Regenerate for changes in earlier patches, apply Lev's changes
          to Visual Studio project file

Patch V4: Regenerate to also have the changes of earlier patches.

Patch V5: Fix unit tests for crypto library missing chacha20-poly1305

Signed-off-by: Arne Schwabe <arne@rfc2549.org>
Acked-by: Lev Stipakov <lstipakov@gmail.com>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <20200221100746.7065-1-arne@rfc2549.org>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg19499.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>