Tab key doesn't trigger autocomplete for Matter-specific Zephyr CLI commands

[lmpprk]

Problem

In Zephyr CLI the commands would autocomplete or provide possible command suggestions when hitting tab key.

e.g.

uart:~$ kernel
  cycles   reboot   stacks   threads  uptime   version

But Matter-specific commands don't do this.

Proposed Solution

• Backfill and implement the autocompletion/suggestion for the existing commands
• Setup convention/template for future command implementations