This commit adds a qdrant container to the list of supported
Testcontainers.

The qdrant container allows configuration of:

- an API key to authenticate to Qdrant
- an x509 certificate used to secure communication to Qdrant with
  Transport Layer Security
- a custom configuration file. See
  https://qdrant.tech/documentation/guides/configuration/

Closes testcontainers#992

Qdrant uses rustls for TLS, which does not accept IPv4 or IPv6 addresses as the hostname in SNI, adhering
to RFC 6066: https://www.rfc-editor.org/rfc/rfc6066#page-7

Sending an IPv4 or IPv6 address as the hostname in SNI causes the handshake to be rejected and
qdrant to log

WARN rustls::msgs::handshake: Illegal SNI hostname received "127.0.0.1"

By default, .NET on linux sends the DNS name in the URI in Server Name Indication (SNI),
irrespective of whether it's an IP address or not. In order to resolve this, a custom
Host request header is added, per

dotnet/runtime#20876 (comment)

This commit moves the wait for strategy to
use the readyz endpoint. If a certificate has
been specified, perform the check with TLS and
allow any certificate to pass validation.

The qdrant gRPC client uses .NET Framework build
of Grpc.Net.Client, which uses WinHttpHandler. The
wiring up is easier on net462 if net462 is targeted
specifically. Same reason why the Milvus container
also targets net462 (testcontainers#1131 (comment)).

…dotnet into qdrant-container