samples: bluetooth: fixes tmap sample issues

- Added support for CAP_COMMANDER in configuration to allow tmap-cg
 and tmap-ums roles to be validated. For CG and UMR, CAP INITIATOR
 and CAP COMMANDER roles are mandatory. Without this support, config
 "CONFIG_BT_TMAP_CG_SUPPORTED" & "CONFIG_BT_TMAP_UMS_SUPPORTED" are
 not getting defined and function fail during "valid_tmap_role()".

- Replaced iso_pool user-data size from 8 to kconfig setting
 "CONFIG_BT_CONN_TX_USER_DATA_SIZE" to allow conn_iso_send()
 to success. Without it the user-data for iso_pool configured
 with value 8 but the kconfig "BT_CONN_TX_USER_DATA_SIZE" has
 default value as 16 causes conn_iso_send() function to fail.

- Updated audio_timer_timeout() with expected QoS interval value
 to send ISO_SDU at every 10msec instead of 1 sec. Without this sink
 device receiving null-sdu most of the time as ISO interval is 10ms
 and unicast-source keep sends SDU at every 1 sec.

Signed-off-by: Nirav Agrawal <nirav.agrawal@nxp.com>