Aio-quakeml-client

* Added Python 3.12 support.
* Bumped dateparser to 1.2.0.
* Bumped haversine to 2.8.1.
* Bumped library versions: black, flake8, isort.
* Migrated to pytest.
* Code quality improvements.

* Added Python 3.11 support.
* Removed deprecated asynctest dependency.
* Bumped library versions: black, dateparser, xmltodict, haversine.

* Improved extensibility for implementing libraries.
* General code improvements.

* Remove unnecessary print statement.
* Remove string capitalisation in two instances.

* Extract last timestamp from entries' creation info.
* Fix potential bug where dynamic URL is not yet initialised.

* Made feed URL dynamically configurable in case the QuakeML feed supports parameters that could change with each call.