Modernized App

[Lichtblitz]

Hi SkyJedi :-)

Try out my changes at https://dice.istbeiuns.de/

PR #16 got closed because I renamed my main branch.

I have been a long time user of your dice roller and had the idea to spend some time and effort to modernize the app as a form of give-back. My primary goal was to improve the user interface, especially on smaller screens. I think it's ready for public scrutiny. Please let me know what you think.

If you decide to accept the PR and host it yourself, I will take down my demo page, which I have temprarily connected to the same firebase-db in order to better compare before/after.

Changes:

• upgrading dependencies; fixing breaking changes
• functional paradigm used to make components less verbose
• switched from plain CSS to bootstrap
• switched popups to bootstrap modals to kick out an outdated dependency
• switched to SCSS to adjust the default bootstrap theme to make it look closer to the previous App version
• overhauled the login page form and introduced (opt-in) cookies to remember values
• migrated deprecated refs-API for react properties
• everything that's clickable now acts like a button to make it very clear to the user what's interactable
• all sections can now be minimized to show only the most important information/controls
• slightly changed the order of the dice to always have a consistent theme in each row
• messages and chats are color coded
• message for resetting the destiny pool now contains the previous state
• rolling brings the result automatically into view; most likely only relevant for small screens, for example on mobile
• creating and editing a character now happens inside the character block, not inside a separate modal
• added a few animations
• added ability to collapse dice results to only show the rolled amount per symbol

Bugfixes:

• fixed XSS vulnerabilities - not in the cleanest way possible but for now it has to be 100% backwards compatible
• two edge cases where undefined fields were accessed
• initiative tracker now works with a single entry as well