Turning the "importsNotUsedAsValues" TS config value to "error".
This will require us to use `import type` instead of `import` when we are importing a value that is only used as a type (and therefore that is dropped by the Typescript compiler).
Why this change?
This is a requirement to be able to use Svelte in the future. See https://github.com/sveltejs/svelte-preprocess/issues/206#issuecomment-663193798
I honestly don't believe text objects look good on map, and in real maps, I think text should be written on tiles.
However, for a variety of use cases (like in test maps in the /maps/test directory, it can be useful to be
able to display some text easily on a map.
This PR adds the ability to display this text.
Note: the "font" support cannot work correctly, as Tiled is listing fonts from the local
system, and those fonts are not available in a browser.
