feat(Core): bootstrap Auth configuration before other categories, and fixed analytics integration tests

[ruiguoamz]

Description of changes:

• Removed AWSMobileClient for getting identityId.
• Move configuration file under "~/AWSPinpointPluginIntegrationTests" and add README.md as instruction to run the integration test.

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

[lawmicha]

can you change the name of this PR to something like
`feat(core): bootstrap Auth configure before other categories, fix analytics tests" ?

we are trying to follow conventional commits btw (https://www.conventionalcommits.org/en/v1.0.0/)

[lawmicha]

this is a fairly important change, it would be good to update the description to talk about the change to configuring Auth first, or very least mention it

[palpatim]

Please verify that removing the file AmplifyPlugins/Analytics/HostApp/Configuration/amplifyconfiguration.json still allows all of the frameworks, both library and test, to compile.

[palpatim]

Let's set up an array of Categories to be initialized, in order, then we can inspect membership in the array rather than multiple not-equals checks below. We can aid this with an extension on CategoryType:

In CategoryType.swift

public extension CategoryType {
    var category: Category {
        switch self {
        case .analytics:
            return Amplify.Analytics
        case .api:
            return Amplify.API
        case .auth:
            return Amplify.Auth
        case .dataStore:
            return Amplify.DataStore
        case .hub:
            return Amplify.Hub
        case .logging:
            return Amplify.Logging
        case .predictions:
            return Amplify.Predictions
        case .storage:
            return Amplify.Storage
        }
    }
}

Then here in AmplifyConfiguration.swift:

let manuallyConfiguredCategories = [CategoryType.logging, .hub, .auth]
for categoryType in manuallyConfiguredCategories {
    try configure(categoryType.category, using: configuration)
}

let remainingCategories = CategoryType.allCases.filter { !manuallyConfiguredCategories.contains($0) }
...