Gracefully handle broken mappings that are part of a plan (error when editing, prevent migrating)

[mturley]

Noticed when trying to fix https://bugzilla.redhat.com/show_bug.cgi?id=1958649 in kubev2v/forklift-ui#591. There is a possibility that if the wizard's prefill effect can't find mapping source/target resources matching the mapping CR embedded in the plan, it will fail to prefill those values and the mapping steps will use defaults (acting as if you're creating a new plan). We should detect these missing items and report an error of some kind on the mapping step, indicating that the mapping present originally can't be used, so it has reverted to defaults. We should also make sure a plan with broken mappings associated causes a condition on both the mapping CR and the plan CR. We already handle this for shared mappings on the mappings page using the isMappingValid helper which could be reused, but we should make sure the plan is blocked from migrating in this case too.

[github-actions]

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[github-actions]

This issue was closed because it has been stalled for 15 days with no activity.

[github-actions]

This issue is stale because it has been open 120 days with no activity. Remove stale label or comment or this will be closed in 15 days.

[github-actions]

This issue is stale because it has been open 120 days with no activity. Remove stale label or comment or this will be closed in 15 days.

[yaacov]

part of: #801

[yaacov]

addressed by #801 and #966