Feature: Add fallback option in case of any failure

[subhamkrai]

This is a feature request to have a fallback option in case any error occurred during migration.

[travisn]

As discussed in huddle, a few points to consider:

• If there is a failure, abort the tool so multiple failures will not be hit at the same time across multiple PVC conversions.
• Rolling back a failure is a non-goal due to the significantly increased complexity of the tool.
• Logging and documentation of the tool is the most critical part to deal with failure. We want to guide users through a failure, but we don't need to automate it.