Settings: Remove circular dependency on CPowerManager

[garbear]

This removed one (of many) of settings' dependencies. Enum values were placed in a new files because settings still relies on the value, but at least the depend on PowerManager is broken.

@FernetMenta is the use of a reference here OK because settings is always available?

Motivation and Context

Split out from #14302.

How Has This Been Tested?

Compiles and runs on OSX.

Types of change

• Bug fix (non-breaking change which fixes an issue)
• Clean up (non-breaking change which removes non-working, unmaintained functionality)
• Improvement (non-breaking change which improves existing functionality)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that will cause existing functionality to change)
• Cosmetic change (non-breaking change that doesn't touch code)
• None of the above (please explain below)

[FernetMenta]

is the use of a reference here OK because settings is always available

@garbear I think it is ok for now and points out the issue we have with settings: we should split them by components.

[garbear]

jenkins build this please