add concrete BleakScanner and BleakClient classes

This allows us to put all of the documentation, including platform-
specific quirks, for BleakScanner and BleakClient in one place. Docs
for these classes are move to new sub-pages of the API docs page and
the backend docs are moved to the backend pages of the docs.

It will also allow us to eventually eliminate quite a bit of duplicated
code from the backends by moving it to these shared classes.

Several methods that provided duplicate functionality have been
deprecated (previously they were required because of backend
implementation details but can now be safely removed from the
top-level classes).

.github/workflows/format_and_lint.yml

@@ -21,4 +21,4 @@ jobs:
             -   name: Lint with flake8
                 run: pipx run poetry run flake8 . --count --show-source --statistics
             -   name: Build docs
-                run: READTHEDOCS=True pipx run poetry run make -C docs html
+                run: pipx run poetry run make -C docs html

CHANGELOG.rst

@@ -15,6 +15,11 @@ Changed
 * Relax ``async-timeout`` version to support different installations. Merged #1009.
 * ``unpair`` function of ``BleakClient`` in WinRT backend can be called without being connected to remove stored device information
 * Use relative imports internally. Merged #1007.
+* ``BleakScanner`` and ``BleakClient`` are now concrete classes. Fixes #582.
+* Deprecated ``BleakScanner.register_detection_callback()``.
+* Deprecated ``BleakScanner.set_scanning_filter()``.
+* Deprecated ``BleakClient.set_disconnected_callback()``.
+* Deprecated ``BleakClient.get_services()``.
 
 Fixed
 -----