Provides List of Client-Side Examples

[OlegDokuka]

Basic RSocket Client-Side

Motivation:

To give more understanding on how to use RSocket-Swift, this PR adds a list of simple rsocket examples which demonstrate on how to use rsocket-swift in the vanilla scenario as well as integration with frameworks like Spring Boot Messaging RSocket and the use of hand-written composite-metadata support

Modifications:

Adds 5 files in tests/Examples

Result:

More samples on rsocket-swift

Signed-off-by: Oleh Dokuka odokuka@vmware.com

[dnadoba]

The examples are now executables and use RSocketNIOChannel instead of RScoketTSChannel to support linux as well.
I have added apple/swift-argument-parser as a dependency to make it possible to configure the examples from CLI.
We can now run the examples by running swift run time-client-example, swift run twitter-client-example or swift run vanilla-client-example.
They also can show help information:

% swift run twitter-client-example --help
OVERVIEW: connects to an RSocket endpoint using WebSocket transport, requests a stream at the route `searchTweets` to search for tweets that match the `searchString`
and logs all events.

USAGE: twitter-client-example [<search-string>] [--host <host>] [--port <port>] [--limit <limit>]

ARGUMENTS:
  <search-string>         used to find tweets that match the given string (default: RSocket)

OPTIONS:
  --host <host>           (default: demo.rsocket.io/rsocket)
  --port <port>           (default: 80)
  --limit <limit>         maximum number of tweets that are taken before it cancels the stream (default: 1000)
  -h, --help              Show help information.

As WebSocket transport is not fully implemented, they do not work yet but I work on that next.