[2.2] Commissioning script output should preserve whitespace

I noticed when looking at commissioning script results that whitespace was missing, such as indentation. (This makes YAML, and any other output which uses indentation for readability, difficult to interpret.)

If I open the inspector and find the <code/> element the commissioning script text is inside, the problem is fixed if I add the following attribute to the <code/> element:

   style="white-space: pre-wrap;"

I also tried "white-space: pre;", but this is not ideal because it would require horizontal scrolling.

Note that pre-wrap should probably also be used on the Settings page for custom commissioning scripts. If a line in a custom commissioning script extends beyond the right margin, currently we have a separate bug that describes how the controls for the script can be hidden (for example, you cannot delete a custom commissioning script in the UI if a line in the script is too long). A fix to that issue should consider applying the same fix there as well.