[PROPOSAL] Give ability to customize the loading indicator

[ghost]

Hi! It will be very good to have access to change the progress indicator.

Could you please add a new parameter to the Crop widget, so we can pass our custom progress indicator widget? Many thank in advance.

[vixez]

I have this feature already in PR: #49

[chooyan-eng]

@PTLam25
Thank you for the feedback.

@vixez
Thank you for your PR! I'll check this.

[chooyan-eng]

I just added progressIndicator parameter to Crop class. You can check the change in #75 .

@vixez
I checked your PR and I could make the PR above using your idea. I didn't merge your PR as is but I separated "loading widget" part into #75 and fixed param name and how default widget is set. Thanks!