The completion callback currently only accepts a JavaScriptModuleScript.
The same callback will need to be used for ClassicScript scripts as well
so allow the callback to accept any Script type. The single existing
outside caller already stores the result as a Script.
We have a new, improved string type coming up in AK (OOM aware, no null
state), and while it's going to use UTF-8, the name UTF8String is a
mouthful - so let's free up the String name by renaming the existing
class.
Making the old one have an annoying name will hopefully also help with
quick adoption :^)
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 patch adds various algorithms required to fetch and link module
scripts.
Some parts such as actually creating a request and error handling are
not implemented or use temporary non spec compliant code to get us
further.
Co-authored-by: davidot <davidot@serenityos.org>