Hi there.
Regarding what you want to clip and the button, on what places you want to inject that mechanism? I see that you have used Google for example, but do you want any website that has an input text field on it? If so, there should be "copy" clipboard button near every input text that extension can find. If I am mistaking, can you elaborate where I am mistaking?
Also, when do you plan to start the project and when is the deadline, if there is one?
Anyways, feel free to hit me up so we can talk more on this. I am very responsive. All the best