Add blur tool as annotation option

[ionleu]

Is your feature request related to a problem? Please describe.

Sometimes I need to hide sensitive info (like emails or IDs) in screenshots, but there's no easy way to do that with the current annotation tools.

Describe the solution you'd like

Add a blur tool to the annotation options so I can quickly blur out parts of the image.

Describe alternatives you've considered

Right now I have to edit the image in another tool before uploading, which is time-consuming.

Additional context

Would be great if I could adjust the blur strength and size, like in Loom or macOS screenshot editor.

[rahulrana701]

I can add this.

[ionleu]

@rahulrana701,
great!

Let's start with #230 and we can continue with these once that one is completed.