Add lint: struct derives `Reflect` and e.g. `PartialEq`, but is not doing `#[reflect(PartialEq)]`

[janhohenheim]

[alice-i-cecile]

An example in the wild: bevyengine/bevy#15187

[MrGVSV]

After the monstrous task of bevyengine/bevy#18307 I think I'll try to give this one a go