feat: Optionally save preflight bundles to disk

[banjoh]

Description, Motivation and Context

This PR introduces a way to store a bundle of collected data when running preflights. The changes are

• Always store a bundle to the current working dir when we run preflight command. The format is preflightbundle-YYYY-MM-DDTHH_MM_SS.tar.gz
• Add a BundlePath option for SDK users to pass in a bundle path to store collected preflight data in that directory.

Demo: https://asciinema.org/a/NBz1y7erRhATItuFR0F8N6tMr

Fixes: sc-111576

Checklist

• New and existing tests pass locally with introduced changes.
• Tests for the changes have been added (for bug fixes / features)
• The commit message(s) are informative and highlight any breaking changes
• Any documentation required has been added/updated. For changes to https://troubleshoot.sh/ create a PR here

Does this PR introduce a breaking change?

• Yes
• No

[banjoh]

Docs PR replicatedhq/troubleshoot.sh#578

[banjoh]

@adamancini

just watched the asciinema, does the feature write the tarball only if you click s to save or does it just happen always?

As for your question, the tarball is always saved to disk

I suppose the followup is: does it save the tarball if you also pass non-interactive flag?

It saves it on both cases. I made a change to always log when its saved to disk

[nvanthao]

LGTM