Add Option for Single Column, Three Column Display of Entries

[Iune]

Currently, entries are split across two columns, regardless of how many entries there are. In smaller contests, it may be better to have a single column display of entries. Similarly, in larger contests, it may be better to have a three column display of entries.

• Add the option to set the number of columns to arrange the entries. (If the user selects more columns than there are entries, use the highest possible value for the number of columns.)

Note: this issue was manually transferred from GitLab.