[enhancement]: Relocate json schemas somewhere more sensible

# Enhancement

All of our jsonschemas are hidden down under `cloudinit/config/schemas/`, which doesn't make sense:

a) these files contain data not Python code
b) some of these files are not specific to configuration modules
c) the `__init__.py` was never required

These file should exist in a directory under the top directory, probably named something like `schema` (alternatively `jsonschema` or maybe something more generic like `data`).

Expected changes:
- code in cloudinit/, specifically schema.py
- test/unittest/
- `setup.py`
- possibly distro packaging too (presumably avoidable with setup.py finesse)