Add window dims and background image to ofxOscilloscopeSettings.xml

[produceconsumerobot]

Describe the feature
Add the ability to specify the window dimensions and a background image in ofxOscilloscopeSettings.xml

Describe the solution you'd like
Ideally ofxOscilloscopeSettings.xml would look like:

<window>
  <width>1500</width>
  <height>900</height>
  <backgroundImagePath>data/assets/backgroundImage.png</backgroundImagePath>
  <multiScope>
    <x>0.000000000</x>
    <y>55.000000000</y>
    ...
  </multiScope>
</window>

I think backgroundImage.png should automatically stretch to fit the full window.

[produceconsumerobot]

@nitin710 my analysis is that Claude is correct that it will be significantly easier to do:

<window>
  <width>1500</width>
  <height>900</height>
  <backgroundImagePath>data/assets/backgroundImage.png</backgroundImagePath>
</window>
<multiScope>
  <x>0.000000000</x>
  <y>55.000000000</y>
  ...
</multiScope>

because ofxOscilloscope::loadScopeSettings(string filename) takes a filename input and expects a structure with multiScope at the highest level. I believe putting <window> adjacent to <multiScope> thereby avoids the need to touch multiple repositories at this time.