fix(forms): throw error if wrong control container for reactive forms

[kara]

This PR ensures that there are clearer error messages for incorrect or missing reactive form containers.

Before
Case 1: Missing parent formGroup

<input formControlName="name">

Error: No provider for ControlContainer

Case 2: Trying to use a regular form tag without a formGroup

<form>
   <input formControlName="name">
</form>

Error: Cannot setParent of null

After

Now in these cases, the error will be a bit more descriptive:

Error: formControlName must be used with a parent formGroup directive. 
You'll want to add a formGroup directive and pass it an existing FormGroup instance 
(you can create one in your class).

Example:

<div [formGroup]="myGroup">
   <input formControlName="firstName">
</div>

In your class: 

this.myGroup = new FormGroup({
   firstName: new FormControl()
});

[kara]

Got verbal LGTM from Victor

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