Allow customisation of barcode view

[SimonChaumet]

Warning: this could be a breaking change

For an application I need to set the barcode background to a minimal padding but the padding is always set to 10. Is there a reason for this thing ?

I can create a pull request but I don't know what could be the best thing to do:

• allow padding customization only
• allow full customization with backgroundStyle

[fgrs]

I also need this