Ability to disable `EventHandler` automatic listener assignments

Prerequisites

• I have searched for duplicate or closed feature requests
• I have read the contributing guidelines

Proposal

Hey,

I was wondering why my uninitialized elements in my code — provided they have the data tags in place — get automatically initialized with the bootstrap modules I include somewhere else in my JS/TS code.

Then, after some debugging and tracing I figured it out: it's the EventHandler.on calls on the bottom of respective bootstrap module code.

I'd like to turn this off, but by looking at the code, right now I have no possibility of doing so.

The proposal is to be able to specify bootstrap that I will manually initialize my elements, and Bootstrap should not automatically do so by listening for various events on the document node.

Motivation and context

I am using webpack and typescript to bundle my modules together using the latest bootstrap with vanilla JS. Problem is, once I include one Bootstrap module somewhere (Modal or Collapse are fine examples of this), it automatically starts listening on elements that I didn't even specify it to listen on. This makes development a bit frustrating, as I like to have full control over where I initialize modules.

I don't want Bootstrap modules to take over elements I don't specifically specify. Testing gets really frustrating when I want to see the places I forgot to initialize stuff, and I don't want it to automatically happen by code I have no control over.

Start by tracing the EventHandler.on calls at the bottom of the Bootstrap module code, using Modal and Collapse as the examples mentioned in the issue. Determine how an opt-out for automatic document listeners would affect manual initialization and the other modules. Done should allow users to disable automatic assignments while preserving explicit module initialization.