chore(storage): replace node-fetch with native fetch in tests

[swseverance]

The test infrastructure appears to run on Node 18, where native fetch is guaranteed. There is no reason to depend on node-fetch in the testing code — replace the imports with native fetch and remove node-fetch and @types/node-fetch from devDependencies.

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Fixes #8336 🦕

[gemini-code-assist]

Code Review

This pull request removes the node-fetch dependency and its associated types, transitioning the project to the native fetch API. Feedback identifies potential issues resulting from this change, including the shift from Node.js Readable streams to Web ReadableStreams in response bodies and compatibility conflicts between native fetch and the form-data package. Additionally, a correction was requested for an invalid @types/node version in package.json.

[swseverance]

It has come to my attention that the storage library may in fact be running tests in node 14 as well as node 18. If in fact tests are running in node 14 then they will likely fail, as fetch will not be available. Would the project maintainers be open to updating the storage library to no longer support node 14? It seems like many of the other packages require node >= 18