[Mono.Security]: Cleanup the MonoTlsProvider's certificate validation code. (#3674)
* [Mono.Security]: Remove Mono.Security.Interface.IMonoTlsContext.
This interface is not actually used anywhere anymore, so we can also
just get rid of it.
* [System]: Removed unused private TLS classes.
* [Mono.Security]: Cleanup the MonoTlsProvider's certificate validation code.
Each TLS Provider now has its own certificate validator and there is no
automatic fallback anymore. We only have three different TLS Providers,
"legacy", "appletls" and "btls" - and legacy is the only one which used
the managed validator. Both AppleTls and BTLS provider their own validator,
which invokes some native API.
All of the following were internal APIs.
* MonoTlsProvider.HasCustomSystemCertificateValidator has been removed.
* MonoTlsProvider.InvokeSystemCertificateValidator() has been renamed
into ValidateCertificate() and is now abstract.
14 files changed: