Add inital support for vector tiles

[jplitza]

Description

Add support for vector tiles.

Motivation and Context

Fixes #74.

Adding to the reasoning there, vector tiles can easily be customized using styles, without setting up a rendering server.

How Has This Been Tested?

Not yet / there are still bugs:

• Zooming a vector tile layer with the sidebar shown has weird effects. (If the map is fullscreen, it works correctly.)

Screenshots/links:

Checklist:

• My code follows the code style of this project. (CI will test it anyway and also needs approval)
• My change requires a change to the documentation.
  • I have updated the documentation accordingly.

[jplitza]

The zoom problem seems to be caused by leaflet-active-area, called here:

meshviewer/lib/map.ts

Lines 47 to 55 in 8131fae

	function mapActiveArea() {
	map.setActiveArea({
	position: "absolute",
	left: sidebar.getWidth() + "px",
	right: 0,
	top: 0,
	bottom: 0,
	});
	}

I don't see an easy fix for that, yet.