Calculate the mode correctly, return the 'maximum' value in case of multiple modes.

[Megh-Thakkar]

#94

[Megh-Thakkar]

Since we are only creating dummy reports for compositional tasks, the mode validation correctly follows this now: https://github.com/ServiceNow/WorkArena/blob/main/src/browsergym/workarena/tasks/compositional/dash_do_base.py#L346, https://github.com/ServiceNow/WorkArena/blob/main/src/browsergym/workarena/tasks/compositional/dash_do_base.py#L477

[aldro61]

@Megh-Thakkar for the cheat function, it's ok to use the max value as tiebreaker and just use the largest of the modes. However, for the validation function, we must accept any value that is a valid mode. You should move it to its one condition case, just like max/min and make sure you allow any number that is a valid mode.