Trader NPC & Lake of Rage "Town"

This adds the Trader NPC to the Lake of Rage and restores its "town" environment.

The town is themed around evolution. The mart sells all the "normal" evolution stones, aiming to solve Johto's "stone problem" for Pokemon like Vulpix and Bellsprout. The Trader NPC actualises this, being at a point where most Pokemon are around Level 35-40, as is how we balanced it on Cinnabar Island in KEP.

The text is mostly revolved around the Gyarados, but this could shift.

The Gym isn't done - I don't have time to sort it at the moment - but I am thinking of making it a Pre-Gym. This doesn't make a lot of sense though, so maybe it should be changed to be the tower seen in an earlier build.

constants/map_constants.asm

@@ -60,6 +60,9 @@ ENDM
 	map_const ROUTE_42,                                    30,  9 ;  5
 	map_const ROUTE_44,                                    30,  9 ;  6
 	map_const MAHOGANY_TOWN,                               10,  9 ;  7
+	map_const LAKE_OF_RAGE_TRADER_HOUSE,					4,  4 ;  8
+	map_const LAKE_OF_RAGE_POKECENTER_1F,                   5,  4 ;  9
+	map_const LAKE_OF_RAGE_MART,                            6,  4 ; 10
 	endgroup
 
 	newgroup DUNGEONS                                             ;  3

constants/mart_constants.asm

@@ -42,4 +42,5 @@
 	const MART_MT_MOON
 	const MART_INDIGO_PLATEAU
 	const MART_UNDERGROUND
+	const MART_LAKEOFRAGE
 DEF NUM_MARTS EQU const_value