fix(api-graphql): events url pattern; non-retryable error handling

[iartemiev]

Description of changes

1. Fixes HTTP -> realtime URL transformation for events
2. Fixes non-retryable error handling
3. Tests for ^

Description of how you validated changes

1. Manual
2. Added unit tests

Checklist

• [x] PR description included
• [x] yarn test passes
• [x] Unit Tests are changed or added

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[github-actions[bot]]

⚠️ This PR includes changes to the "aws-amplify" package.json file, which can have library-wide implications.

Please ensure that this PR:

• Does not manually change "@aws-amplify/*" dependency versions, which may misalign core dependencies across the library

• Remove any export paths without a major version bump

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