Settings: Remove environment groups from settings

[iLLiCiTiT]

Brief description

Removed logic related to environment groups which were implemented at the beginning of settings implementation but are not used anymore.

Description

Environment groups were stored using metadata to easily find their values in whole settings but the approach had a lot of limitations and was more magical then practical. Goal of PR is to make clearer api and remove unused code (that should not be used). All removed functions were kept for backwards compatibility of older builds but it is not needed for more then 2 minor releases. Also removed backwards compatibily of removed functions from start.py .

Additional info

Removed functions

• openpype.lib.env_tools.get_global_environments - was replaced by openpype.settings.get_general_environments
• openpype.settings.get_environments - was replaced by openpype.settings.get_general_environments
• openpype.settings.lib.find_environments - not used anymore

Testing notes:

1. Environments should be loaded as they did.

[mkolar]

unable to start

>>> Reading Poetry ... OK
>>> run disk mapping command ...
disk mapping args:: ['subst', 'P:', 'C:\\']
>>> Logging to server is turned ON
>>> loading environments ...
  - for Avalon ...
  - global OpenPype ...
Traceback (most recent call last):
  File "C:\Users\milan\code\OpenPype\start.py", line 1175, in <module>
    boot()
  File "C:\Users\milan\code\OpenPype\start.py", line 1086, in boot
    set_openpype_global_environments()
  File "C:\Users\milan\code\OpenPype\start.py", line 269, in set_openpype_global_environments
    from openpype.settings import get_general_environments
  File "C:\Users\milan\code\OpenPype\openpype\settings\__init__.py", line 27, in <module>
    from .entities import (
  File "C:\Users\milan\code\OpenPype\openpype\settings\entities\__init__.py", line 73, in <module>
    from .base_entity import (
  File "C:\Users\milan\code\OpenPype\openpype\settings\entities\base_entity.py", line 18, in <module>
    from openpype.lib import PypeLogger
  File "C:\Users\milan\code\OpenPype\openpype\lib\__init__.py", line 47, in <module>
    from .env_tools import (
ImportError: cannot import name 'get_global_environments' from 'openpype.lib.env_tools' (C:\Users\milan\code\OpenPype\openpype\lib\env_tools.py)