- `percent_field` should be declared on `platypush.schemas.dataclasses`
level, since it's not specific to the `system` plugin.
- Added a common `SystemBaseSchema` that takes care of calling
`_asdict()` if the object is passed as a `psutil` object instead of a
dict.
Plus, `platypush.schemas.system` has now been split into multiple
submodules to avoid a single-file mega-module with all the system
schemas definitions.
Also, there is now a single `Cpu` entity being exported, with a nested
hierarchy structured like:
```
cpu
-> cpu_info
-> cpu_times
-> idle
-> user
-> system
-> ...
-> cpu_load
-> ...
```
Fabio Manganiello
Fabio Manganiello