Object paths can have non-ascii characters. Device dicts will
have unicode values. Forming a string using both will cause the
object path to be coerced to UTF8, which currently causes a
UnicodeDecodeError. This causes _get_response() to not return
and the recosntructor hangs.
The call to _full_path() is moved outside of _get_response()
(where its result is used in the exception handler logging)
so that _get_response() will always return even if _full_path()
raises an exception.
Unit tests are refactored to split out a new class with those
tests using an object name and the _full_path method, so that
the class can be subclassed to use an object name with non-ascii
characters.
Existing probe tests are subclassed to repeat using non-ascii
chars in object paths.
Change-Id: I4c570c08c770636d57b1157e19d5b7034fd9ed4e
Closes-Bug: 1679175
83750cf79c