Fix Typos / Use Box Constants

The Celadon City scripts that give Eevee misspelled it as Eeevee. Fixed.

The comment explaining `boxRSEggsUnlocked` in the `ExternalEventFlags` struct had an incorrect deposit requirement listed and was fixed.

Also, replaced the literals with the `TOTAL_BOXES_COUNT` and `IN_BOX_COUNT` constants in `pokemon.c`'s `IsPokemonStorageFull` function. Thanks hjk321 for pointing that out.

src/pokemon.c

@@ -3799,8 +3799,8 @@ static bool8 IsPokemonStorageFull(void)
 {
     s32 i, j;
 
-    for (i = 0; i < 14; i++)
-        for (j = 0; j < 30; j++)
+    for (i = 0; i < TOTAL_BOXES_COUNT; i++)
+        for (j = 0; j < IN_BOX_COUNT; j++)
             if (GetBoxMonDataAt(i, j, MON_DATA_SPECIES) == SPECIES_NONE)
                 return FALSE;