Add an error to ResolveError for failure to deliver an intent to an app

[kriswest]

Enhancement Request

Add a IntentDeliveryFailed error to the ResolveError enumeration.

Use Case:

The ResolveError enumeration provides standard string for failures you might get back when raising an intent or findIntent runs into a problem (e.g. the are no apps available for that intent, the resolver isn't available or the user cancelled resolution). However, it doesn't include a standardized error for cases where it succeeded in resolving to an app or app instance, but couldn't deliver the intent and context to it. This might occur because:

1. the app failed to add an intent listener or,
2. added an intent listener but not for the right type
3. or failed in some other way (e.g. it closed immediately).

Additional Information

There is some overlap with the errors added in the recently merged PR for targetting app instances:

• 450 allow intents to target app instances #509
• TargetAppUnavailable
• TargetInstanceUnavailable

However, these are intended to indicate that a specifically targetted app or instance is not available to be started or has been closed (e.g. option for an instance was shown in a resolver, but it closed before delivery or the target app couldn't be started for some reason). This handles case 3 above, but not 1 or 2.

Clear documentation of which error to use when will be added to ensure the various situations are easily differentiated.