Adding arduino-router-client tool

[cmaglie]

Motivation

Adding a tool to ease the debugging of RPC clients.

Change description

This PR adds a new tool called arduino-router-client.

$ ./arduino-router-client  -h
Send a MsgPack RPC REQUEST or NOTIFICATION.

Usage:
  ./arduino-router-client [flags] <METHOD> [<ARG> [<ARG> ...]]

Send REQUEST:      ./arduino-router-client [-s server_addr]    <METHOD> [<ARG> [<ARG> ...]]
Send NOTIFICATION: ./arduino-router-client [-s server_addr] -n <METHOD> [<ARG> [<ARG> ...]]

  <METHOD> is the method name to request/notify,
  <ARG> are the arguments to pass to the method:
      - Use 'true', 'false' for boolean
      - Use 'null' for null.
      - Use integer values directly (e.g., 42).
      - Use the 'f32:' or 'f64:' prefix for floating point values (e.g. f32:3.14159).
      - Use '[' and ']' to start and end an array.
      - Use '{' and '}' to start and end a map.
        Keys and values should be listed in order { KEY1 VAL1 KEY2 VAL2 }.
      - Any other value is treated as a string, or you may use the 'str:' prefix
        explicitly in case of ambiguity (e.g. str:42)

Flags:
  -h, --help            help for ./arduino-router-client
  -n, --notification    Send a NOTIFICATION instead of a CALL
  -s, --server string   Server address (file path for unix socket) (default "/var/run/arduino-router.sock")

some usage examples:

$ ./arduino-router-client ping { a [ 1 2 b ] c d }
Sending parameters:
- a:
    - 1
    - 2
    - b
  c: d
Got RPC response:
- a:
    - 1
    - 2
    - b
  c: d
$ ./arduino-router-client ping { version 2.15.3-rc.1 name Max surname Mad }
Sending parameters:
- name: Max
  surname: Mad
  version: 2.15.3-rc.1
Got RPC response:
- name: Max
  surname: Mad
  version: 2.15.3-rc.1
$ ./arduino-router-client $/version 
Sending parameters:
[]
Got RPC response:
0.0.0-dev

Additional Notes

Reviewer checklist

• PR addresses a single concern.
• PR title and description are properly filled.
• Changes will be merged in main.
• Changes are covered by tests.
• Logging is meaningful in case of troubleshooting.