Make clearer how to obtain verbose output upon network error

[RudolfCardinal]

RNC:

• User received error message "There was a problem sending your completed tasks to the server"; this is from CamcopsApp::uploadFailed. No other info given ...

MB:

• It is possible to turn on verbose logging in single user mode. You have to jump through a number of settings screens to get there (Settings and Advanced Settings if I remember correctly).

Code relates to m_silent in NetworkManager, ultimately related to CamcopsApp::isSingleUserMode().

Possibilities to make this more obvious to users (or could do several):

• Add this to docs.
• Put instructions within the short-form dialogue on how to switch to verbose mode.
• [Probably not: operate a "shadow" detailed logbox and offer to show it upon failure.]

[RudolfCardinal]

Looks great. Two trivial things:

• bool try_again_with_log could be const bool ...
• Task titles in translations use for format "Original [translation]" for the avoidance of doubt and the preservation of acronyms; therefore Compulsive Exercise Test should translate to Compulsive Exercise Test [kompulsiv træningstest]

and you've fixed some of my Danish too; thank you! I think that's it; otherwise good to go.