Allow Modal popups on Interaction followup

[Hyperclaw79]

Currently, Modals can only be sent in the initial response to an interaction.
While this seems like a good UX practice as it makes us respond to the interaction as soon as possible, it's a strict limitation. There are edge cases where we need to defer the response and then send the Modal in a followup.

Here are 2 example use cases:

1. We need to a perform a slightly time consuming computation (or maybe a DB call) before populating the labels for the TextBoxes on the Modal.
2. We want to initiate a Modal after a few Select interaction. (in a quiz for example)

So, allow the developers to have the flexibility to control the timing of the Modal popups.