Add a prop for updating the Media Upload label

[ajmaurya99]

Is your enhancement related to a problem? Please describe.

I would like to update the Media Upload label via props, currently its just 'Add Image' - https://github.com/10up/block-components/blob/3f113d3d8de843f0cbe0f32cd34764d78486fcc5/components/media-toolbar/index.js#L45

Designs

No response

Describe alternatives you've considered

No response

Code of Conduct

• [X] I agree to follow this project's Code of Conduct

[itsajay1029]

Can I work on it @ajmaurya99 @fabiankaegy ?

[fabiankaegy]

@itsajay1029 You are more than welcome to create a PR for this :)