Resolve "Fix uneditable error reports"

Closes #625

See merge request arsnova/cards!1188

Change Markdeep.js Version to 1.13

See merge request arsnova/cards!1178

Test new type of image with unprivileged user

See merge request arsnova/cards!1180

Add new dark mode

Closes #618, #602, #603, #611, #573, #34, #30, #35, #32, #31, #29, #609, #12, #11, #10, #14, #5, #4, #1, and #2

See merge request arsnova/cards!1177