Bluetooth: shell: Add support to retrieve A2SRC record

Adds to BT shell app functionality to trigger to be found on remote
A2SRC UUID. Implements user callback to read resolved response data
and uses existing SDP client API to read attributes values.

> HCI Event: Number of Completed Packets (0x13) plen 5
        Num handles: 1
        Handle: 77
        Count: 1
> ACL Data RX: Handle 77 flags 0x02 dlen 48
      Channel: 64 len 44 [PSM 1 mode 0] {chan 0}
      SDP: Service Search Attribute Response (0x07) tid 2 len 39
        Attribute bytes: 36
        Continuation state: 0
        Combined attribute bytes: 89
          Attribute list: [len 84] {position 0}
            Attribute: Service Record Handle (0x0000) [len 2]
              0x00010005
            Attribute: Service Class ID List (0x0001) [len 2]
              UUID (3) with 2 bytes [0 extra bits] len 3
                Audio Source (0x110a)
            Attribute: Protocol Descriptor List (0x0004) [len 2]
              Sequence (6) with 6 bytes [8 extra bits] len 8
                UUID (3) with 2 bytes [0 extra bits] len 3
                  L2CAP (0x0100)
                Unsigned Integer (1) with 2 bytes [0 extra bits] len 3
                  0x0019
              Sequence (6) with 6 bytes [8 extra bits] len 8
                UUID (3) with 2 bytes [0 extra bits] len 3
                  AVDTP (0x0019)
                Unsigned Integer (1) with 2 bytes [0 extra bits] len 3
                  0x0102
            Attribute: Browse Group List (0x0005) [len 2]
              UUID (3) with 2 bytes [0 extra bits] len 3
                Public Browse Root (0x1002)
            Attribute: Bluetooth Profile Descriptor List (0x0009) [len 2]
              Sequence (6) with 6 bytes [8 extra bits] len 8
                UUID (3) with 2 bytes [0 extra bits] len 3
                  Advanced Audio Distribution (0x110d)
                Unsigned Integer (1) with 2 bytes [0 extra bits] len 3
                  0x0102
            Attribute: Unknown (0x0100) [len 2]
              Advanced Audio [len 15]
            Attribute: Unknown (0x0311) [len 2]
              0x0001
< ACL Data TX: Handle 77 flags 0x00 dlen 12
      L2CAP: Disconnection Request (0x06) ident 10 len 4
        Destination CID: 65

Change-Id: I8938d9eebda31f3d252ff49adc1a96abfcbc5751
Signed-off-by: Arkadiusz Lichwa <arkadiusz.lichwa@tieto.com>