Allowing Resource Sharing as an IAB launch option

# Feature Request

## Motivation Behind Feature
With the release of 5.0.0 one of the changes includes resource sharing between the main webview and the IAB again. There are some utilizations of the IAB where the lack of resource sharing is currently used as a security feature.

## Feature Description
When an InAppBrowser gets launched, with versions preceding 5.0.0, resource sharing was not possible.

With the new 5.0.0 released, one of the features includes the ability to share resources between the main webview and the IAB.

This is problematic for applications where the application design relies on resources being segregated.

Having resource sharing as an option on IAB launch would solve this issue that is preventing applications from upgrading to 5.0.0 and would also cater for all use cases in the current and past versions.

## Alternatives or Workarounds
The only current alternative is to not upgrade to 5.0.0

The issue does not name files, tests, or launch entry points. Start by locating the InAppBrowser launch API and its Android and iOS implementations, then define how an explicit resource-sharing option should be represented and verified while preserving segregated resources by default.

Written by the indexing model from the issue text.