Use modules' fishing loot tables to randomly override fished items

[Vftdan]

Add fishing event handler to the base Module class that rerolls one of the three fish loot categories (independently from the result got from the original vanilla roll, so skewing the effective probabilities) with weights that should emulate vanilla behavior (taking into account the player's Luck effect, Luck Of The Sea enchantment, and whether the fishing bobber is currently in open water) and randomly selects an item from the module's corresponding loot table proportional to its chance to replace the original fished item or preserves the original item with a chance of $1.0 - \sum\text{of chances in the module's selected loot table}$.

Fixes #292