Create a helm 3 renderer plugin

[dlespiau]

jkcfg/jk#288 is the core of a plugin system. We should now be able to what was envisoned in jkcfg/jk#133.

• Write a helm3 plugin (by re-using the helm 3 packages used to implement helm template)
• Write a a shim Chart object wrapping the render() call to this plugin so we end up with something like helm render support jk#133 (comment).

[squaremo]

I would honestly just jump straight to helm3 -- the sentiment within the Helm community seems broadly in favour of doing that ASAP. The libraries will be more amenable to reuse and working without a server component.

[dlespiau]

Can I use helm2 charts with helm3?

[errordeveloper]

I believe charts meant to be 100% compatible.

[dlespiau]

Cool, we'll start with helm 3 then!