Inappropriate item levels for new items

The following items have levels that are not reflective of when they are acquired in the progression line:

Great Explosive Grenade Satchel: level 16

Prodigious Explosive Grenade Satchel: level 16

Ornate Blunderbuss: level 16

Additionally, the two new grenades don't have a higher durability than the Refined version. Simple = 15, Refined = 20, Great/Prodigious = 20 durability.

The level and durability values should be updated to reflect their place in progression.