Refactor RemoteConfig ConfigInfo swig generation

[a-maurice]

Description

Provide details of the change, and generalize the change in the PR title above.

Refactor Remote Config's ConfigInfo class to be handwritten instead of using SWIG to generate the class.

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Testing

Describe how you've tested these changes.

https://github.com/firebase/firebase-unity-sdk/actions/runs/8165714354

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Type of Change

Place an x the applicable box:

• [ ] Bug fix. Add the issue # below if applicable.
• [ ] New feature. A non-breaking change which adds functionality.
• [x] Other, such as a build process or documentation change.

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