feat(battery_plus)!: Introduce connected_not_charging state on MacOS

[vbuberen]

Description

Adding new connected_not_charging state to MacOS as follow-up to #2275 which introduced such state on Android.
Renamed the state from the initial name suggested in #2275 to be more explicit.

Marking as a breaking change to bring attention to the new state in platform interface and because I have reimplemented MacOS states definition.

Looks like this state can be added for Linux as well, so will open one more PR for Linux platform.

Checklist

• I read the Contributor Guide and followed the process outlined there for submitting PRs.
• I titled the PR using Conventional Commits.
• I did not modify the CHANGELOG.md nor the plugin version in pubspec.yaml files.
• All existing and new tests are passing.
• The analyzer (flutter analyze) does not report any problems on my PR.

Breaking Change

Does your PR require plugin users to manually update their apps to accommodate your change?

• Yes, this is a breaking change (please indicate that with a ! in the title as explained in Conventional Commits).
• No, this is not a breaking change.