Allow larger outputs for test cases

Currently for test cases (e.g. for puzzles), the limit for the input is 10,000 characters, whereas the limit for the output is 1,000 characters.

I don’t know what the rationale for this imbalance is, but I feel that it may be beneficial to set the output limit to 10,000 characters as well, or at least siginificantly larger than 1,000 characters.

Especially for puzzles where you have to output the state of a board, the current limit of 1,000 characters is fairly low. It only allows e.g. 31*31 characters (including newlines) to be output, before hitting the limit.

What is the reason for the current limit? Can it be increased?

The answer might be related to front-end performance. Puzzles might be OK, but imagine printing max chars in multis. I think I even experienced performance degradation once.