Feature: Remote values files

Problem to be solved

We want to make it very easy for developers to distribute new apps. Distributing Helm charts make it easy, but distributing helm chart values files could make it even easier again.

Proposed solution

Sometimes you're changing important code and need a new chart, but I would bet that many many times you don't need a new chart, you just want to change values in the chart easily (docker image, network, genesis/chain info).

Having new charts per use case is fine, and people may use that way for separation of concern/branding/removing flags, but potentially a lot could be managed with good organisation of values files. Similarly, being able to just distribute a values file for a commonly used chart might be faster and easier for devs than merging to a chart repository somewhere.

e.g. a dev could encourage people to run:

# Installing 
obol install ethereum/ethereum-node --values https://ethpandaops.io/static/howth-testnet-nethermind-lighthouse.json

# or 
helm upgrade --install ethereum/op-node --values https://raw.githubusercontent.com/user/gist.json

Start by tracing the obol install entry point and how it invokes Helm, then compare the proposed remote --values URL flow with the shown helm upgrade --install example. Done means the CLI can safely consume remote values files for installation and upgrade scenarios, with the supported behavior documented and verified.