Using them will lead to "not supported yet" errors soon after, but it's a start
to get to handling separate modules.
The idea is that `foo` can now also be `Bar.foo`, `Bar.Baz.foo`, `foo.Struc.fld`
can be `foo.Bar.Baz.Struc.fld`, etc.
The next steps are to enable the lookups to handle this paths, and to provide
ways to load the external modules to feed these lookups.
This is just a bunch of `sed` calls:
```shell
sed -i 's/ScopeSet/ScopeName.Set/g' compiler/**/*.ml*
sed -i 's/ScopeMap/ScopeName.Map/g' compiler/**/*.ml*
sed -i 's/StructMap/StructName.Map/g' compiler/**/*.ml*
sed -i 's/StructSet/StructName.Set/g' compiler/**/*.ml*
sed -i 's/EnumMap/EnumName.Map/g' compiler/**/*.ml*
sed -i 's/EnumSet/EnumName.Set/g' compiler/**/*.ml*
sed -i 's/StructFieldName/StructField/g' compiler/**/*.ml*
sed -i 's/StructFieldMap/StructField.Map/g' compiler/**/*.ml*
sed -i 's/StructFieldSet/StructField.Set/g' compiler/**/*.ml*
sed -i 's/EnumConstructorMap/EnumConstructor.Map/g' compiler/**/*.ml*
sed -i 's/EnumConstructorSet/EnumConstructor.Set/g' compiler/**/*.ml*
sed -i 's/RuleMap/RuleName.Map/g' compiler/**/*.ml*
sed -i 's/RuleSet/RuleName.Set/g' compiler/**/*.ml*
sed -i 's/LabelMap/LabelName.Map/g' compiler/**/*.ml*
sed -i 's/LabelSet/LabelName.Set/g' compiler/**/*.ml*
sed -i 's/ScopeVarMap/ScopeVar.Map/g' compiler/**/*.ml*
sed -i 's/ScopeVarSet/ScopeVar.Set/g' compiler/**/*.ml*
sed -i 's/SubScopeNameMap/SubScopeName.Map/g' compiler/**/*.ml*
sed -i 's/SubScopeNameSet/SubScopeName.Set/g' compiler/**/*.ml*
```
... and reformat
