[tModLoader] ExampleMod - Example Dash Accessory [Showcase #2]

A showcase of the Example Dash Accessory item, an accessory that potentially may be in ExampleMod.

STATS:
+2 defense

SPECIAL EFFECTS:
Allows the user to dash in any of the four cardinal directions by
double-tapping a movement key in the desired direction.

===CHANGES===
- Added a priority system to force this accessory's dash to be out-prioritized by vanilla dashes. Possible idea for an ItemLoader or PlayerHooks hook?
- Increased the Up direction's dash velocity (scales with ExampleDashAccessory.DashVelocity) to make it as fast as the other cardinal directions' dashes.

[Showcase