[BUGFIX beta] Ensure proper .toString() of default components.

[rwjblue]

In older Ember versions the default components were generally labelled as Ember.Component or Ember.TextField via the NAME_KEY property on the class itself. During the glimmer-vm upgrade which landed during the 3.1 canary cycle the custom NAME_KEY was lost for Ember.TextField.

This commit removes needless usage of NAME_KEY (not needed since our normal Ember.Object instance's .toString methods check for the factories own toString properly), and updates the actual paths to match the new JS modules API locations (thus reducing more "globals" shenanigans).

[mmun]

j/w where is this relied on?

[rwjblue]

CoreObject.prototype.toString uses the factories toString for the instances own toString display.

ember.js/packages/ember-runtime/lib/system/core_object.js

Lines 571 to 578 in 8ef8dc6

	toString() {
	let hasToStringExtension = typeof this.toStringExtension === 'function';
	let extension = hasToStringExtension ? `:${this.toStringExtension()}` : '';
	let ret = `<${this[NAME_KEY] || FACTORY_FOR.get(this) || this.constructor.toString()}:${guidFor(this)}${extension}>`;
	return ret;
	}

normally that means that we call makeToString on the resolver

ember.js/packages/container/lib/container.js

Lines 384 to 390 in 8ef8dc6

	toString() {
	if (this.madeToString === undefined) {
	this.madeToString = this.container.registry.makeToString(this.class, this.fullName);
	}
	return this.madeToString;
	}

https://github.com/ember-cli/ember-resolver/blob/13f05eb45d2aef0fc860486f18e0897425362b43/addon/resolvers/classic/index.js#L131-L133

but these specific classes are not in the resolver

[rwjblue]

The reason I started digging into this (@rwwagner90 and I paired on this PR) was that the inspector had some tests that were trying to confirm that we had a valid string representation.

[mmun]