Bluetooth: shell: audio: Extend `vcs init` with opt params
Bluetooth: shell: audio: Extend `vcs init` with opt params

Extend the `vcs init` command with optional parameters to set the
initial VCS state including volume level, mute state and step size.
This is needed to pass qualification test cases listed below:
VCS/SR/CP/BV-01-C,
VCS/SR/CP/BV-02-C,
VCS/SR/CP/BV-02-C,
VCS/SR/CP/BV-04-C

Signed-off-by: Mariusz Skamra <c73850bd0bf85e95dce44c2ce1418ca55c1b6c5d@codecoup.pl>

zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,galak/zephyr,galak/zephyr,finikorg/zephyr,finikorg/zephyr,finikorg/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,galak/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr