Add support for Mbed TLS 4

Add support for Mbed TLS 4

This commit adds support for Mbed TLS 4. This version comes with some
drastic changes. The crypto library has been completely redesigned, so
the contents of crypto_mbedtls.c are moved to crypto_mbedtls_legacy.c
and crypto_mbedtls.c handles the crypto for version 4.

Mbed TLS 4 also removed the feature for looking up a crypto algorithm by
name, so we need to translate algorithm names to Mbed TLS numbers in
OpenVPN. The tables are not yet complete. For symmetric algorithms, I
have added AES and Chacha-Poly which should be enough for most use
cases.

Change-Id: Ib251d546d993b96ed3bd8cb9111bcc627cdb0fae
Signed-off-by: Max Fillinger <maximilian.fillinger@sentyron.com>
Acked-by: Arne Schwabe <arne-openvpn@rfc2549.org>
Gerrit URL: https://gerrit.openvpn.net/c/openvpn/+/1441
Message-Id: <20260123164746.7333-1-gert@greenie.muc.de>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg35401.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>