ref: This is a general refactor to enhance readability and maintainability

[GuiLeme]

What does this PR do?

This basically refactors a bunch of functions/components to enhance readability and maintainability in the long term.

Apart for that refactor, I also renamed the labels for the filters in the presenter modal (and changed the logic accordingly).

This PR is made to maintain the whole plugin behaviour as is (except for the labels I mentioned), so if you find anything out of ordinary, please, let me know.

Closes Issue(s)

Closes #13

More

With this PR, the Presenter modal looks like (which is indeed better to grasp what each option does):

[Arthurk12]

The refactor looks good and indeed enhances the readability/maintainability of the code.
However I found 2 issues:

1. I don't know if it was an issue before, but late joiners are prompted with the random picked user over the audio modal and session details modal. And the problem is that it gets into a state where the modal can't be closed. So the user is stuck.
2. There is a warning being log into the console about app element not defined. Something related to modals too:

hook.js:608 Warning: react-modal: App element is not defined. Please use `Modal.setAppElement(el)` or set `appElement={el}`. This is needed so screen readers don't see main content when modal is opened. It is not recommended, but you can opt-out by setting `ariaHideApp={false}`. Error Component Stack
    at ModalPortal (ModalPortal.js:79:5)
    at Modal (Modal.js:73:5)
    at P (styled-components.browser.esm.js:30:19658)
    at PickUserModal (component.tsx:29:40)
    at PickRandomUserPlugin (component.tsx:27:19)

[antobinary]

I don't know if it was an issue before, but late joiners are prompted with the random picked user over the audio modal and session details modal.

This is an issue today, without this PR

[ramonlsouza]

issue 2 also occurs without the PR (tested in local setup)