Upload dialog/Design/Bad uploads

Possible reasons for bad uploads

 * Not understanding what kind of files are helpful for Commons and other projects (selfies are useful for social networks, for example).
 * Not understanding the meaning of Own work.
 * Not understanding the basics of Copyright law.
 * Malice.
 * Disregard for legal notices (they aren't enforced as often on other websites).
 * The context of the upload, that is the page it is being uploaded from is forgotten or ignored.

Proposed solutions

 * https://phabricator.wikimedia.org/T120867#1914007
 * https://phabricator.wikimedia.org/T120867#1903246
 * https://phabricator.wikimedia.org/T120867#1887088
 * https://phabricator.wikimedia.org/T120867#1868598
 * https://phabricator.wikimedia.org/T120867#1884287