Radio Button with object as value uncheckes on reset/setvalue/patchvalue

#### Bug, feature request, or proposal:
Bug

#### What is the expected behavior?
Just read the next part it will become obvious.

#### What is the current behavior?
When using objects as the value for MatRadioGroup and MatRadioButton the current implementation lacks a `compareWith` property like the current implementation of MatSelect. Normally the radio button will only do a reference based comparison of the value compared to the radio groups value to see if a button should be checked. This is an issue because I am using an API to get the values for the radio group and buttons this interferes with this way of doing a comparison.

However MatRadioButton does have a property called `checked` which I can use. I wrote my own compare method and have it check the current value of the MatRadioGroup with the current value of the MatRadioButton and return true to set the `checked` state of the radio button.

When I use `reset(value)`, `setValue(value)`, or `patchValue(value)` or click on a radio to change the value of the MatRadioGroup, everything works. However performing this twice with the same object results in the radio being unchecked.

#### What are the steps to reproduce?
https://stackblitz.com/edit/angular-material-radio-not-checked-bug

Press the set button twice.
OR
Press the set button then press the reset button twice
OR
Change the selected radio by clicking on a new option and then press the reset button twice
OR
Do not change anything and right away (after a fresh page load) press the reset button

#### What is the use-case or motivation for changing an existing behavior?
Allowing me to use objects or arrays with MatRadioGroup/MatRadioButton while preserving the functionality of a simple reset button for my form.

#### Which versions of Angular, Material, OS, TypeScript, browsers are affected?
material 5 and 6

#### Is there anything else we should know?
This may be related to:
https://github.com/angular/material2/issues/11368

I also think that this feature request would also help potentially fix this issue depending on implementation:
https://github.com/angular/material2/issues/10495

Commencez par la reproduction StackBlitz liée et examinez la gestion de value/checked dans MatRadioGroup et MatRadioButton. Reproduisez des appels répétés à reset, setValue et patchValue avec des valeurs d’objet, puis suivez la manière dont la deuxième mise à jour est comparée. C’est terminé lorsque le bouton radio sélectionné reste coché après chaque mise à jour répétée et après la modification des options.

Rédigé par le modèle d'indexation à partir du texte de l'issue.