OpenSSL 4.x support in TaurusTLS

[JPeterMugaas]

Recently, the OpenSSL developers released an Alpha Release of OpenSSL 4.x at:

https://github.com/openssl/openssl/releases/tag/openssl-4.0.0-alpha1

In response to this, we have started on support for this release in hopes that we will be ready when the OpenSSL makes a release version of OpenSSL 4.0.0.

1. We build the current source-code to make a non-production release including something that works with ARM64EC (see bug report: 4.0.0-alpha1 build fails for Windows arm64ec (Visual Studio) openssl/openssl#30361 ) from the trunk. This build will only be available to until the next release of OpenSSL 4.
2. We added the TaurusTLSHeaders_ech unit that exposes functions that provide Encrypted Client Hello (ECH) support as well as a prerequisite TaurusTLSHeaders_hpke unit.
3. We also adjusted some of the other headers for functions that were dropped in the OpenSSL 4 code as well as adding the appropriate opaque types to the TaurusTLSHeaders_types header file.
4. The ASN1_STRING type is now opaque meaning that you need to use the "get" and "set" functions instead of directly accessing the ASN1_STRING fields directly.