There’s no direct expression function to use, but you can use the python built-in urllib to unescape a sanitized URL. You could put this into a runScript binding, either directly or by defining a simple helper function in a project/shared script.
You would then construct a binding on your web browser component’s URL property as follows: runScript('project.url.unescape', 0, {source/of/escaped/url})
Every time the source property changes (wherever you’re getting these sanitized URLs from), it will fire the binding, which will run the project script and return the human-readable URL to the web browser component.