Add HomematicIP Cloud Config Flow and Entries loading (#14861)

* Add HomematicIP Cloud to config flow

* Inititial trial for config_flow

* Integrations text files

* Load and write config_flow and init homematicip_cloud

* Split into dedicated files

* Ceanup of text messages

* Working config_flow

* Move imports inside a function

* Enable laoding even no accesspoints are defined

* Revert unnecassary changes in CONFIG_SCHEMA

* Better error handling

* fix flask8

* Migration to async for token generation

* A few fixes

* Simplify config_flow

* Bump version to 9.6 with renamed package

* Requirements file

* First fixes after review

* Implement async_step_import

* Cleanup for Config Flow

* First tests for homematicip_cloud setup

* Remove config_flow tests

* Really remove all things

* Fix comment

* Update picture

* Add support for async_setup_entry to switch and climate platform

* Update path of the config_flow picture

* Refactoring for better tesability

* Further tests implemented

* Move 3th party lib inside function

* Fix lint

* Update requirments_test_all.txt file

* UPdate of requirments_test_all.txt did not work

* Furder cleanup in websocket connection

* Remove a test for the hap

* Revert "Remove a test for the hap"

This reverts commit 968d58cba108e0f371022c7ab540374aa2ab13f4.

* First tests implemented for config_flow

* Fix lint

* Rework of client registration process

* Implemented tests for config_flow 100% coverage

* Cleanup

* Cleanup comments and code

* Try to fix import problem

* Add homematicip to the test env requirements