Adding command line arguments for Kotlin examples

[DariusIMP]

Using Clickt to allow users to specify arguments when running examples on Kotlin.

Usage

For instance the ZPub example, you run it using gradle, and providing the arguments the following way:

gradle ZPub --args="<your arguments>"

** Example: **

gradle ZPub --args="-h"

will display the help menu with the available arguments:

> Task :examples:ZPub
Usage: zpub [<options>]

  Zenoh Pub example

Options:
  -e, --connect=<connect>  Endpoints to connect to.
  -c, --config=<config>    A configuration file.
  -k, --key=<key>          The key expression to write to [default:
                           demo/example/zenoh-kotlin-pub]
  -l, --listen=<listen>    Endpoints to listen on.
  -m, --mode=<mode>        The session mode. Default: peer. Possible values:
                           [peer, client, router]
  -v, --value=<value>      The value to write. [Default: "Pub from Kotlin!"]
  -a, --attach=<attach>    The attachments to add to each put. The key-value
                           pairs are &-separated, and = serves as the separator
                           between key and value.
  --no-multicast-scouting  Disable the multicast-based scouting mechanism.
  -h, --help               Show this message and exit

Solves #55

[eclipse-zenoh-bot]

@DariusIMP If this pull request contains a bugfix or a new feature, then please consider using Closes #ISSUE-NUMBER syntax to link it to an issue.

[oteffahi]

gradle ZPub --args="-l tcp/127.0.0.1:7447 -l udp/127.0.0.1:7447" will only listen on UDP port.

As it is, a repeated flag will overwrite itself, so only the last instance counts. For list options (-l, -e), it would be good if we can repeat the flag for each value, as some users are already used to this syntax on Zenoh Rust examples (which support both syntaxes). If we dont support it here, repeating a flag multiple times should error-out to avoid unintended configuration.

[DariusIMP]

gradle ZPub --args="-l tcp/127.0.0.1:7447 -l udp/127.0.0.1:7447" will only listen on UDP port.

As it is, a repeated flag will overwrite itself, so only the last instance counts. For list options (-l, -e), it would be good if we can repeat the flag for each value, as some users are already used to this syntax on Zenoh Rust examples (which support both syntaxes). If we dont support it here, repeating a flag multiple times should error-out to avoid unintended configuration.

I just fixed it.

[oteffahi]

LGTM 👍