* Add dict of attributes to initialize
* Refactor get_attributes() method
Read 5 attributes at the time.
* Add ZCL_INIT_ATTRS attribute to base Zigbee channel
* Update tests and general clusters
* Update channels to use ZCL_INIT_ATTRS
* Update channels to use ZCL_INIT_ATTRS
* Fix tests
* Refactor async_initialize() to be a retryable request
* Maky pylint happy again