Restructure AEPTestUtils internal frameworks

[timkimadobe]

Description

This PR updates the Core project structure to separate the internal frameworks AEPServicesMocks and AEPCoreMocks entirely; dependence on AEPServicesMocks inside AEPCoreMocks files (via import AEPServicesMocks) were causing usage issues for dependent projects trying to use AEPTestUtils, since AEPServicesMocks doesn't exist outside of the Core project.

AEPServicesMocks Compile Sources contain all the local Services mock files and AEPTestUtils files that only depend on AEPServices AEPCoreMocks Compile Sources contain all of AEPServicesMocks + local Core mock files and AEPTestUtils files that depend on Core

Also adds new Core test API to reset the SDK, and marks the EventHub reset API as deprecated:

public extension MobileCore {
    /// Resets the SDK by shutting down and resetting the EventHub.
    static func resetSDK() {
        EventHub.shared.shutdown()
        EventHub.shared = EventHub()
    }
}

extension EventHub {
    @available(*, deprecated, renamed: "MobileCore.resetSDK()", message: "Avoid using EventHub APIs directly. Use MobileCore.resetSDK() instead.")
    public static func reset() {
        shared = EventHub()
    }
}

Imports have also been cleaned up and organized:

<external frameworks, alphabetized>

<internal frameworks, alphabetized>

ex:

import XCTest

@testable import AEPCore
@testable import AEPCoreMocks
import AEPIdentity
import AEPLifecycle
@testable import AEPServices
import AEPSignal

Related Issue

Motivation and Context

How Has This Been Tested?

Screenshots (if appropriate):

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [ ] I have signed the Adobe Open Source CLA.
• [ ] My code follows the code style of this project.
• [ ] My change requires a change to the documentation.
• [ ] I have updated the documentation accordingly.
• [ ] I have read the CONTRIBUTING document.
• [ ] I have added tests to cover my changes.
• [ ] All new and existing tests passed.

[praveek]

@timkimadobe How about organizing the imports as follows:

import Foundation
import XCTest

// AEP module imports
import AEPIdentity
import AEPLifecycle
import AEPSignal

// Testable imports
@testable import AEPCore
@testable import AEPCoreMocks
@testable import AEPServices

[praveek]

Could you also update the Test Utils README.md to clarify what targets a new file should be added to between AEPServiceMocks and AEPCoreMocks?

[timkimadobe]

Thanks for the review @praveek! Updated based on feedback