Verify data table sizes with table_width and assert_table_length macros

This was discussed in #706

It also uncovered some off-by-one issues with defining some constants.

A few structs now use rsreset/_RS to define their offset constants, as discussed in #739

data/radio/buenas_passwords.asm

@@ -1,5 +1,5 @@
 BuenasPasswordTable:
-; there are NUM_PASSWORD_CATEGORIES entries
+	table_width 2, BuenasPasswordTable
 	dw .JohtoStarters
 	dw .Beverages
 	dw .HealingItems
@@ -11,6 +11,7 @@ BuenasPasswordTable:
 	dw .Moves
 	dw .XItems
 	dw .RadioStations
+	assert_table_length NUM_PASSWORD_CATEGORIES
 
                ; string type, points, option 1, option 2, option 3
 .JohtoStarters: db BUENA_MON,    10, CYNDAQUIL, TOTODILE, CHIKORITA

data/radio/channel_music.asm

@@ -1,5 +1,6 @@
 RadioChannelSongs:
-; entries correspond to radio channel ids
+; entries correspond to radio channel ids (see constants/radio_constants.asm)
+	table_width 2, RadioChannelSongs
 	dw MUSIC_POKEMON_TALK
 	dw MUSIC_POKEMON_CENTER
 	dw MUSIC_TITLE
@@ -11,3 +12,4 @@ RadioChannelSongs:
 	dw MUSIC_POKE_FLUTE_CHANNEL
 	dw MUSIC_RUINS_OF_ALPH_RADIO
 	dw MUSIC_LAKE_OF_RAGE_ROCKET_RADIO
+	assert_table_length NUM_RADIO_CHANNELS

data/radio/oaks_pkmn_talk_routes.asm

@@ -1,7 +1,6 @@
 ; Oak's Pokémon Talk will list wild Pokémon on these maps.
 
 OaksPKMNTalkRoutes:
-; there are NUM_OAKS_POKEMON_TALK_ROUTES entries
 	map_id ROUTE_29
 	map_id ROUTE_46
 	map_id ROUTE_30
@@ -17,3 +16,4 @@ OaksPKMNTalkRoutes:
 	map_id ROUTE_45
 	map_id ROUTE_36
 	map_id ROUTE_31
+.End