Handle empty Canvas data in Renderer

[tbreeze-zengenti]

When working with Canvas fields, the API may return different forms of "empty" data:

• null, or
• an array of Block objects where the value field is an empty array []

Previously, consumers of the Canvas React Renderer had to implement their own checks to guard against these cases. Without these checks, rendering could fail or lead to unintended behavior. This inconsistency has also led to multiple internal utilities being created to sanitize the data before rendering.

The intention of this PR is to add a safeguard directly to the Renderer component to gracefully handle these edge cases.

[nflatley-zengenti]

Hi Tim, thanks very much for bringing this issue to our attention and offering a patch that resolves the immediate issues you encountered

We have reviewed the change internally and we believe that patching the return value is likely to cause further issues downstream in other scenarios and as such will not be accepting this change as-is.

So we can isolate the root cause of the issue(s) can we instead have a copy of the raw Canvas JSON output that is causing the problem(s) during Render?

We can use this example to recreate the issue locally and give us the opportunity to find and fix the problem where it originates