Add a package sdk-vanilla to the repository

[lyleschemmerling]

Problem

This repo contains three package variants for 3 different popular frameworks: Angular, React, and Vue. We can reach a larger user base by supplying a variant that will work with any framework using vanilla javascript custom element web components.
Solution

Add a new package "sdk-vanilla" which will add the following web components:

fa-account: a button to redirect to the user's account management page
fa-login: a button component that will redirect the browser to the /app/login endpoint ans start the oauth flow
fa-logout: a button that will redirect the browser to the /app/logout endpoint
fa-register: a button that will redirect the browser to the /app/register endpoint

There should also be a FusionAuthService typescript class that handles all of the intermediate functions, similar to angular's service or the react provider. It should use the same functions from the core package that the other sdks do.

Where applicable the styles should match the existing sdks

Vite should be used to build the library like the other sdks

Some documentation should be created but it does not need to be complete

There should be instructions and examples on how to use in a readme file