Improve handling of steps and changing outside TF

[jradtilbrook]

PR checklist:

• [x] docs/ updated
• [x] tests added
• [x] an example added to examples/ (useful to demo new field/resource)
• [x] CHANGELOG.md updated with pending release information

Notable changes

• This will no longer set steps when a pipeline is being used and vice versa. Doing this simplifies the plan modification downstream

Resolves #507 Resolves #506