Merge changes Ia62aacb0,If14d1a97,Ibc470d3f,I94fafe8a,I4868de5c, ...

* changes:
  [Private GATT] Add Arbiter to share ATT channel
  [Private GATT] Mirror GATT server inside rust module
  [Private GATT] Add to libbluetooth
  [Private GATT] Add GATT server + module
  [Private GATT] Add basic ATT transaction implementation
  [Private GATT] Basic GATT skeleton