fix(plugin): support outputs without inline initialization

[ShacharHarshuv]

Previously, this script would fail with a cryptic message (cannot read property of undefined (reading includes)) for input like:

@Output() myOutput: EventEmitter<string>;

The changes support that use case and:

• Uses the initialization in the constructor to infer the type (and removes it)
• Creates an initialization (= output()) if it doesn't exist