Update content bank upload button to open file picker in a popup instead of new page

Testing scenario 1: Upload in a modal form Login as admin. Access to the Content bank. Click the Upload button. Check a modal form is open to "Upload content". Upload an H5P file (you can use accordion.h5p attached). Save changes. Check you're redirected to the view.php page and the H5P content is displayed. In the content bank cog, select "Replace with file". Check a modal form is open to "Upload content". Upload an H5P file (you can use arithmetic-quiz.h5p attached). Save changes. Check you're redirected to the view.php page and the H5P content is displayed and it's different from the previous one.