Using `removeNullCharacters` on the URL should be completely redundant, given the kind of data that we're passing to the `addLinkAttributes` helper function. Note that whenever we're handling a URL, originating in the worker-thread, in the viewer that helper function is always being used.
Furthermore, on the worker-thread all URLs are parsed with the `createValidAbsoluteUrl` helper function, which uses `new URL()` to ensure that a valid URL is obtained. Note that the `URL` constructor will either throw, or in some cases just ignore them, when encountering `\u0000`-characters during parsing.
Hence it should be *impossible* for a valid URL to contain `\u0000`-characters and we can thus simplify the viewer-code a tiny bit. The use of `removeNullCharacters` is most likely a left-over from back when `new URL()` wasn't generally available in browsers.