fix(Object): Fixes centeredScaling prop type

[HesamSoleymani]

Motivation

centeredScaling type is set to "false" instead of "boolean" in v6
As @ShaMan123 mentioned in this discussion, it looks like a mistake...

Description

  /**
   * When true, this object will use center point as the origin of transformation
   * when being scaled via the controls.
   * <b>Backwards incompatibility note:</b> This property replaces "centerTransform" (Boolean).
   * @since 1.3.4
   * @type Boolean
   * @default
   */
  centeredScaling: false;

Changes

I've just changed centeredScaling type in FabricObjectProps.ts

[ShaMan123]

thanks, could it be that it is optional as well?

[ShaMan123]

Suggested change

	centeredScaling: boolean;
	centeredScaling?: boolean;

??

[HesamSoleymani]

Is it necessary? I mean I think Partial<FabricObjectProps> is being used everywhere so every option is optional...
But if it is necessary, then what about other props which are still not optional in FabricObjectProps ? (such as centeredRotation, selectionBackgroundColor, selectable and ...)

[ShaMan123]

I will give a look and follow up if needed

[ShaMan123]

Can you add a log to the changlog?
Then I can merge

[asturur]

@HesamSoleymani please also change this here:
https://github.com/fabricjs/fabric.js/blob/master/src/shapes/Object/InteractiveObject.ts#L58
to a declare boolean

[HesamSoleymani]

Everything is ok now about this pr?

[asturur]

i think so.
@ShaMan123 wanted to have a look at something, i approved, when he has time he can check and merge or comment.