Motivation:
As an HTTP library, async-http-client should have authentication
support.
Modifications:
This adds a `setBasicAuth()` method to both HTTPClientRequest and
`HTTPClient.Request` and their related unit tests.
Result:
Library users will be able to leverage this method to use basic
authentication on their requests without implementing this in their own
projects.
Note: I also ran the tests (`swift test`) with the
`docker.io/library/swift:6.0-focal` and
`docker.io/library/swift:5.10.1-focal` to ensure linux compatibility.
Signed-off-by: Agam Dua <agam_dua@apple.com>
