Bluetooth: Add gatt-discover command to btshell
Bluetooth: Add gatt-discover command to btshell

This adds gatt-discover which works as follow:

btshell> gatt-discover <bdaddr> <bdaddr_type> <uuid> [start_handle] [end_handle]
bt: bt_gatt_discover (0x0010cb10): uuid 0x180d start_handle 0x0001 end_handle 0xffff
Discover pending
btshell> bt: bt_att_recv (0x0010ed0c): Received ATT code 0x07 len 5
bt: att_handle_find_type_rsp (0x0010ed0c):
bt: att_find_type_rsp (0x0010ed0c): err 0x00
bt: att_find_type_rsp (0x0010ed0c): start_handle 0x000a end_handle 0x0011
Discover found handle 10
bt: bt_gatt_discover (0x0010ed0c): uuid 0x180d start_handle 0x0011 end_handle 0xffff
bt: bt_att_recv (0x0010ed0c): Received ATT code 0x01 len 5
bt: att_error_rsp (0x0010ed0c): request 0x06 handle 0x0011 error 0x0a
bt: att_find_type_rsp (0x0010ed0c): err 0x0a
Discover destroy

Change-Id: Ic0b28f19e4932e26b2eae2d19f62f6be6e1efa9c
Signed-off-by: Luiz Augusto von Dentz <8530c5ea66a1bdbc08f98bfcf183c8be901b5990@intel.com>

fractalclone/zephyr-riscv,zephyriot/zephyr,mirzak/zephyr-os,jamesonwilliams/zephyr-kernel,ldts/zephyr,finikorg/zephyr,runchip/zephyr-cc3220,mirzak/zephyr-os,runchip/zephyr-cc3200,finikorg/zephyr,bigdinotech/zephyr,bigdinotech/zephyr,sharronliu/zephyr,GiulianoFranchetto/zephyr,nashif/zephyr,kraj/zephyr,fbsder/zephyr,GiulianoFranchetto/zephyr,aceofall/zephyr-iotos,zephyriot/zephyr,holtmann/zephyr,bboozzoo/zephyr,finikorg/zephyr,erwango/zephyr,fbsder/zephyr,punitvara/zephyr,pklazy/zephyr,Vudentz/zephyr,fractalclone/zephyr-riscv,aceofall/zephyr-iotos,32bitmicro/zephyr,runchip/zephyr-cc3200,holtmann/zephyr,kraj/zephyr,erwango/zephyr,galak/zephyr,coldnew/zephyr-project-fork,pklazy/zephyr,holtmann/zephyr,mbolivar/zephyr,32bitmicro/zephyr,sharronliu/zephyr,explora26/zephyr,runchip/zephyr-cc3220,jamesonwilliams/zephyr-kernel,jamesonwilliams/zephyr-kernel,zephyrproject-rtos/zephyr,GiulianoFranchetto/zephyr,ldts/zephyr,zephyrproject-rtos/zephyr,mbolivar/zephyr,Vudentz/zephyr,coldnew/zephyr-project-fork,pklazy/zephyr,erwango/zephyr,erwango/zephyr,holtmann/zephyr,erwango/zephyr,mirzak/zephyr-os,ldts/zephyr,Vudentz/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,coldnew/zephyr-project-fork,bigdinotech/zephyr,bboozzoo/zephyr,runchip/zephyr-cc3200,fractalclone/zephyr-riscv,zephyriot/zephyr,bboozzoo/zephyr,mbolivar/zephyr,32bitmicro/zephyr,rsalveti/zephyr,nashif/zephyr,coldnew/zephyr-project-fork,aceofall/zephyr-iotos,tidyjiang8/zephyr-doc,finikorg/zephyr,tidyjiang8/zephyr-doc,runchip/zephyr-cc3220,runchip/zephyr-cc3220,holtmann/zephyr,bigdinotech/zephyr,fractalclone/zephyr-riscv,mbolivar/zephyr,tidyjiang8/zephyr-doc,32bitmicro/zephyr,galak/zephyr,jamesonwilliams/zephyr-kernel,rsalveti/zephyr,sharronliu/zephyr,fbsder/zephyr,tidyjiang8/zephyr-doc,bigdinotech/zephyr,fbsder/zephyr,runchip/zephyr-cc3200,mirzak/zephyr-os,Vudentz/zephyr,punitvara/zephyr,Vudentz/zephyr,nashif/zephyr,sharronliu/zephyr,fractalclone/zephyr-riscv,zephyriot/zephyr,rsalveti/zephyr,zephyriot/zephyr,punitvara/zephyr,punitvara/zephyr,explora26/zephyr,ldts/zephyr,mbolivar/zephyr,tidyjiang8/zephyr-doc,kraj/zephyr,GiulianoFranchetto/zephyr,ldts/zephyr,pklazy/zephyr,punitvara/zephyr,nashif/zephyr,runchip/zephyr-cc3220,aceofall/zephyr-iotos,coldnew/zephyr-project-fork,GiulianoFranchetto/zephyr,zephyrproject-rtos/zephyr,rsalveti/zephyr,bboozzoo/zephyr,mirzak/zephyr-os,galak/zephyr,jamesonwilliams/zephyr-kernel,aceofall/zephyr-iotos,explora26/zephyr,32bitmicro/zephyr,galak/zephyr,explora26/zephyr,nashif/zephyr,rsalveti/zephyr,Vudentz/zephyr,zephyrproject-rtos/zephyr,fbsder/zephyr,kraj/zephyr,sharronliu/zephyr,runchip/zephyr-cc3200,explora26/zephyr,galak/zephyr,bboozzoo/zephyr,kraj/zephyr,pklazy/zephyr