monitor/att: Add decoding support for Volume Control Serice

monitor/att: Add decoding support for Volume Control Serice

This adds decoding support for VCS attributes

> ACL Data RX: Handle 3585 flags 0x02 dlen 7
      ATT: Read Request (0x0a) len 2
        Handle: 0x0017 Type: Volume State (0x2b7d)
< ACL Data TX: Handle 3585 flags 0x00 dlen 8
      ATT: Read Response (0x0b) len 3
        Value: 000000
        Handle: 0x0017 Type: Volume State (0x2b7d)
            Volume Setting: 0
            Not Muted: 0
            Change Counter: 0
> HCI Event: Number of Completed Packets (0x13) plen 5
        Num handles: 1
        Handle: 3585 Address: 49:71:FC:C0:66:C6 (Resolvable)
        Count: 1
> ACL Data RX: Handle 3585 flags 0x02 dlen 7
      ATT: Read Request (0x0a) len 2
        Handle: 0x001c Type: Volume Flags (0x2b7f)
< ACL Data TX: Handle 3585 flags 0x00 dlen 6
      ATT: Read Response (0x0b) len 1
        Value: 01
        Handle: 0x001c Type: Volume Flags (0x2b7f)
            Volume Falg: 1

Signed-off-by: Manika Shrivastava <manika.sh@samsung.com>
Signed-off-by: Ayush Garg <ayush.garg@samsung.com>