Editorial: refactor callers of internal module script graph fetching procedure

[hiroshige-g]

This PR simplifies the call graph around internal module script graph fetching procedure.

This PR makes top-level entry points of module loading

• Fetch a module script graph
• Fetch an inline module script graph (introduced by this PR)
• Fetch a dynamic module script graph (introduced by this PR)
• Fetch a module worker script graph
• The fetch and process the linked resource algorithm for modulepreload links

call fetch the descendants of and instantiate,
that calls fetch the descendants of,
that calls internal module script graph fetching procedure,
that calls fetch the descendants of recursively.

Previously, internal module script graph fetching procedure can be top-level or non-top-level,
and thus calls fetch the descendants of and instantiate or fetch the descendants of accordingly,
depending on the top-level module fetch flag.
This PR makes internal module script graph fetching procedure non-top-level only, and
merges the top-level parts into the top-level entry points of module loading listed above.

This PR slightly changes the timing of FinishDynamicImport on error in resolve a module specifier,
but this doesn't affect observable behavior so much,
because promises are anyway resolved asynchronously.

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/links.html ( diff )
/scripting.html ( diff )
/webappapis.html ( diff )

[hiroshige-g]

@domenic WDYT?

This was a preparation for import maps spec.
This turns out not strictly required by the import maps spec draft, but probably is helpful as a general refactoring.

(I also created a call graph chart but I'm not sure whether this image should be also added)

[domenic]

This seems pretty nice. A couple small things:

• Can you rewrap changed paragraphs using https://output.jsbin.com/maferi ?
• Let's make the names more obvious. I suggest:
  • Fetch an external module script graph
  • Fetch an inline module script graph
  • Fetch an import() module script graph
  • Fetch a module worker script graph

[hiroshige-g]

Let's make the names more obvious.

Sounds good. Renamed.

Also rewrapped lines.

[domenic]

OK, I pushed a few more changes, including the diagram, and it looks good to me now. @hiroshige-g can you check over my changes with your own review?

[hiroshige-g]

Thanks! Your commits look good to me.

The diagram looks nice. How did you prepare the diagram?

[domenic]

I wrote out the SVG by hand. I find it relaxing sometimes :)