Refactor LocalConfig package

[noaabarki]

Describe the solution you'd like Cleanup:

1. Delete LocalConfig(empty struct). Instead, export GetLocalConfiguration function. Add comments to this function.
2. Remove getConfigName and getConfigType. Use const instead.
3. Add setter and getter for token key in the local configuration.
4. Cover these updates with testing. Use pkg/extractor or pkg/httpClinet as reference.

Requirements Golang basic level.