v0.7.0 🧰A service for each internal command, 'user.py' for user commands.

Changes

• Each internal command is now available using either 'service.execute' or 'service.COMMAND' where COMMAND is a command like attr_write, attr_read, ... .
• Fully specified attr_write and attr_read in services.yaml so that UI configuration is more concise and clearly indicates required options.
• Added a default implemetation to make the addition of future commands easier with less code, and avoiding restarts after updates.
• Added the possibility to call commands in local/user.py which is a gread tool to develop your personal commands and/or more general commands you might propose for integration to zha-toolkit.
• Commands, services and parameters are now all defined as constants in the code.