[Overhaul] Implementation of a more consistent & modern UI

[KyleKlus]

Description

This PR is an overhaul of the main ui and it implements the issue #872. More detail on what the PR implements and more documentation in general can be found there.

Changes

• Improved DeckListView
• Improved FlashcardReviewView
• Improved EditModal
• Added a bunch of classes for styling
• Renamed gui files such that they follow a uniform naming convention
• Improved mobile view
• Fixes key listener bug from issue Plugin keyboard shorcut keys do not work in Obsidian notes after reviewing flahscards [BUG] #907
• Fixes bug from issue [BUG] Minor UI issues with the flashcard review modal #773

[st3v3nmw]

Hi, thanks for the contribution! Looks like there are some conflicts since some of the changes are reverting things that have already gone in

[st3v3nmw]

LGTM, thanks.

Please resolve the merge conflicts (caused by merging #902)

[KyleKlus]

I think this PR also fixes the bug in issue #768, as I've changed the mobile view such that this shouldn't be a problem anymore, but I don't have a IOS device, so I can't test it.

[SimoAbjaou]

Hello, can you please see this ticket : #1101
Can you help me the fix it ?

[KyleKlus]

Sry I think I cant help you here, but I haven't changed anything in regards with how the markdown is rendered. I just transformed the containers around the markdown rendered content. Thus I couldn't have changed anything how an Image is rendered.