[V3] Add the ConnectTimeout property on the service client config for the …

[normj]

Description

In the .NET 8 target we have access to the ConnectTimeout. This PR exposes the ability to set the ConnectTimeout on the service client.

In the V4 version of this AWSSDK.Extensions.NETCore.Setup was also updated but in this V3 PR it was not. That is because in V3 extends from the ClientConfig so it automatically inherits the properties. In V4 we removed the inheritance so I need to copy the ConnectTimeout to AWSSDK.Extensions.NETCore.Setup and add the logic to copy the setting the service client config.

Motivation and Context

This will help in scenario the SDK is trying to connect to a bad host and gets stuck trying to create the connection for a long period. If the user sets the connect timeout the SendAsync will timeout after the connect timeout has expired and since it is an IO exception the SDK will retry possibly to a different host.

Testing

Dry run successful: DRY_RUN-394333cd-113a-4bbe-a5f0-a13ba692b64c
Manually confirmed by setting a low connect timeout that the SDK does do a retry when the connect timeout happens.

[normj]

Ideally I would like to default this to DefaultConfiguration.ConnectTimeout instead of null but changing the default timeout would be a breaking change. Maybe when we do a 4.1 we can reconsider the default.