add context and switches to PlayerQuitEvent

[Hydroxycobalamin]

This PR modernizes the PlayerQuitEvent. Additionally to that it adds the following:

Switches

@Location true, requested by Chaps79 on Discord. cause:<cause> to only process the event when it matches the specific cause (only on Paper).`

Context

<context.cause> returns an ElementTag of the cause of the quit (only on Paper)

The PaperImplementation makes also use of the non-deprecated Methods

• quitMessage() to return the quit message
• quitMessage(component) to set the quit message.