This patch implements all changes to the specification touching the
subset of module script fetching we support.
Notably it adds parts of the specification for supporting import maps.
With this we are also able to get rid of a non standard workaround for a
spec issue we discovered while initially implementing module scripts :^)
This patchs adds the Web::HTML::Script subclass ModuleScript and
JavaScriptModuleScript as a type of ModuleScript as well as various
algorithms related to JavaScript module scripts.
Co-authored-by: davidot <davidot@serenityos.org>
