Describe the PR

Vue supports components defined as factory functions, except when the component is lazy loaded (via a lazy import, or require, that return promises), as it assumes the component is either an object or a Vue.extended object (although this requirement is not documented).

This PR changes how the component is defined, switching back to the plain object format instead of a component factory function, and by replacing props with a self-overwriting lazy getter to generate the props on first access, and subsequently cache the results in the component's options:

export default {
  name: 'BCol',
  get props() {
    delete this.props
    return (this.props = generateProps())
  },
  render(h) {
    //...
  }
}

The first access (via Vue.component(...), Vue.extend(...) or $createElement(...)) will generate the prop definitions and cache them.

Fixes #3080

Side Note; the original issue should really be fixed in Vue (allowing a lazy loaded component to return a factory function)

PR checklist

What kind of change does this PR introduce? (check at least one)

• Bugfix
• Feature
• Enhancement
• ARIA accessibility
• Documentation update
• Other (please describe) Code refactor

Does this PR introduce a breaking change? (check one)

• No
• Yes (please describe)

The PR fulfills these requirements:

• It's submitted to the dev branch, not the master branch
• When resolving a specific issue, it's referenced in the PR's title (i.e. [...] (fixes #xxx[,#xxx]), where "xxx" is the issue number)
• It should address only one issue or feature. If adding multiple features or fixing a bug and adding a new feature, break them into separate PRs if at all possible.
• The title should follow the Conventional Commits naming convention (i.e. fix(alert): not alerting during SSR render, docs(badge): update pill examples, fix typos, chore: fix typo in README, etc). This is very important, as the CHANGELOG is generated from these messages.

If new features/enhancement/fixes are added or changed:

• Includes documentation updates (including updating the component's package.json for slot and event changes)
• New/updated tests are included and passing (if required)
• Existing test suites are passing
• The changes have not impacted the functionality of other components or directives
• ARIA Accessibility has been taken into consideration (Does it affect screen reader users or keyboard only users? Clickable items should be in the tab index, etc.)

If adding a new feature, or changing the functionality of an existing feature, the PR's
description above includes:

• A convincing reason for adding this feature (to avoid wasting your time, it's best to open a suggestion issue first and wait for approval before working on it)