Linting is specific to the chart versions. A v2 and v3 chart will
lint differently.
To accomplish this, packages like engine need to be able to handle
different chart versions. This was accomplished by some changes:
1. The introduction of a Charter interface for charts
2. The ChartAccessor which is able to accept a chart and then
provide access to its data via an interface. There is an
interface, factory, and implementation for each version of
chart.
3. Common packages were moved to a common and util packages.
Due to some package loops, there are 2 packages which may
get some consolidation in the future.
The new interfaces provide the foundation to move the actions
and cmd packages to be able to handle multiple apiVersions of
charts.
Signed-off-by: Matt Farina <matt.farina@suse.com>