Integrate with existing Bolt Inventory

[MikaelSmith]

Focus on interactive approach to interacting with Bolt targets rather than script-driven.

• Easier to read logs across a variety of systems.
• Pre-configured direct filesystem access.
• Copy files between systems.

Add a new plugin that reads an existing Bolt inventory and presents items in that inventory as a hierarchy you can navigate.

• Explore that inventory with Wash. Entries should include any information in the inventory as metadata.
• Hierarchy could have: organize by groups and subgroups. Nodes not in a group are in an implicit all group, but that encompasses everything, so we should probably have a special group name for these.
• Implement SSHFS over that inventory.

Plan

• Add volume.FS core entry and ssh exec transport as external plugin features (#692)
• Release and document external plugin features (#693)
• Implement external plugin features in wash-ruby (puppetlabs-toy-chest/wash-ruby#27)
• Create Bolt plugin (puppetlabs-toy-chest/boltwash#1)
• Update Wash docs with reference to new boltwash external plugin

[ekinanp]

Could use signal for other Bolt actions not captured by Wash primitives like run_script, run_plan, etc, though we'd need to extend signal to support all of that.

[MikaelSmith]

I think that's a different facet of this, more aligned with #249.

[MikaelSmith]

Be careful not to pull in puppet as a dependency when loading Bolt as a library. Also, we can likely pre-compute the entire hierarchy the first time we run list.