Web Components

[laosb]

In constructing some components, we found we end up in having too long class names for sub elements in a specified component. The better way to resolve it is using Web Components. At the same time, we would try to continue the development in a JS-free way. That means we would only make use of HTML templates at this moment, and would not develop JS-heavy or JS-required components like calendar.

Some more new components will be merged here from the PWA version of HDU Help. Currently it's not yet released to public, and this ticket will be ready to tackle right after the first release candidate of HDU Help.