Remove importMetaHook

[kriskowal]

@patrick-soquet notes that we can remove the complication of an importMetaHook by instead reflecting needsImportMeta on StaticModuleRecord instances. This is consistent with the property we already expect in the SyntheticStaticModuleRecord protocol. By reflecting needsImportMeta, we can move the concern to loadHook. The implementer of a loadHook is in a position to decide whether or not to elaborate the importMeta they attach to a module descriptor, based on the presence of needsImportMeta on the underlying StaticModuleRecord.

[Jack-Works]

If we remove this, we'll lost the ability of doing #13

[kriskowal]

@Jack-Works Per #13 (comment), I would like to for now ignore the motivating use-case for revealing the module environment record or module exports namespace on import.meta.self and proceed with #67. Any simplification will streamline this proposal. Please let me know what you think.

[Jack-Works]

I think it's OK for now.