Imported custom property false positive analysis

[idoros]

The CSS custom property analyzeInit hook is wrongly considering any named imported symbol that starts with -- as a custom property and register a symbol for it. This is wrong as a CSS class might also start with --.

This should be fixed by not assuming the type from the import at the analyze flow, and only creating a custom property symbol when encountering a @property --prop, --prop or var(--prop). And adding an import reference if one with the same name exist, similarly to how classes and other symbols work.

see playground for reproduction