Python bindings for all custom exception types

[franzpoeschel]

Is your feature request related to a problem? If so, please describe.
For our new exception types in Error.hpp, we have bindings for Python inside https://github.com/openPMD/openPMD-api/blob/dev/src/binding/python/Error.cpp. For older ones, such as no_such_attribute_error, we don't. This means that it is currently impossible in Python to catch an exception thrown e.g. by get_attribute.

Describe the solution you'd like

1. Add those missing bindings
2. Maybe take the chance to move those exceptions into Error.hpp and into the error namespace.

[franzpoeschel]

They're
unsupported_data_error in include/openPMD/IO/AbstractIOHandler.hpp
and
no_such_attribute_error in include/openPMD/backend/Attributable.hpp