Merge branch 'bugfix/id9561_bt_status_check' into 'master'

component/bt: bug fix of lack of checking bluetooth stack status inside API functions

Add an API function for checking bluetooth stack status: whether it is uninitialized, initialized or enabled.
The function is intended to be used by users to check the bluetooth stack status, also, it is used inside bluetooth API functions to ensure the stack is in valid state.

See merge request !405