Add debug event support

[cdhoffmann]

The SDKs often needs to change its standard business logic to enable debugging/testing workflows. We need an event structure that external systems can follow to generate an event that communicates to the listening SDK extension that it should operate in a debug mode - a mode outside of expected production behavior if one exists.

This commit adds an eventSource "com.adobe.eventSource.debug" to identify such events.
Further, it adds utility methods to identify the eventType and eventSource provided within the data.debug content of such events.
Structure:

{
        "name" : "......",
        "type" : "com.adobe.eventType.system",
        "source" : "com.adobe.eventSource.debug",
        "data" : {
            "debug": {
                "eventType": "<DEBUG_EVENT_TYPE>",
                "eventSource": "<DEBUG_EVENT_SOURCE>"
            },
             "someOtherKey":  {
               ....
               }
         }
}

Usage:

var debugType = Event.debugEventType
var debugSource = Event.debugEventSource

Related Issue

Motivation and Context

The SDKs often needs to change its standard business logic to enable debugging/testing workflows. We need an event structure that external systems can follow to generate an event that communicates to the listening SDK extension that it should operate in a debug mode - a mode outside of expected production behavior if one exists.

This commit adds an eventSource "com.adobe.eventSource.debug" to identify such events.
Further, it adds utility methods to identify the eventType and eventSource provided within the data.debug content of such events.

How Has This Been Tested?

• Unit tests

Screenshots (if appropriate):

n/a

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.

[cdhoffmann]

Ran swiftFormat and fixed a bunch of whitespace issues, apologies for the extra file changes.

[sbenedicadb]

looks good with one little recommendation to clean up the implementation of the extension vars

[sbenedicadb]

i think we can just clean these up like this:

    var debugEventType: String? {
        debugEventData?[Event.DEBUG_EVENT_TYPE_KEY] as? String
    }