Add debug info to Pages::LookupPath::LegacyStorageDisabledError

What does this MR do?

I just want to have this field in kibana so I can visually make sure that they all come from the same project and then proceed with disabling write access to the NFS

Screenshots (strongly suggested)

Does this MR meet the acceptance criteria?

Conformity

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Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
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Security

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Related to #327599 (closed)