Separate processcore/{formatter,unit} into its own library
Summary:
This moves Formatter and Unit out of ProcessCore and into its own Formatter library.
This allows us to reuse them in other places, like a new sensor library that will be
posted later.
It includes a declarative plugin that makes things available to QML.
It also contains a small unit test for Formatter.
Test Plan:
- The new unit test passes.
- KSysGuard still runs correctly.
Reviewers: Plasma, davidedmundson
Reviewed By: Plasma, davidedmundson
Subscribers: zzag, ngraham, plasma-devel
Tags: Plasma
Differential Revision: https://phabricator.kde.org/D27869