[Feat] - Adding circular cropper corner design with custom color support

[bhagyae5308]

We are using the library to show crop image. We are having a requirement to show circular crop corner design with custom color. This library doesn't have support for the same. In order to meet the requirement, I have added some changes in the CropOverlayView class. Have tried to expose builder methods to set the cropper corner design.

Checking if can I create a pull request to this branch for the same changes.
Below is the screenshot for the work done based on our requirement.

[Canato]

Nice work! @bhagyae5308 feel free to drop the PR =D

[stale]

Let's keep this mess organised! This issue has been automatically marked as stale because it has not had recent activity. =( It will be closed if no further activity occurs. Thank you for your contributions.