Finish Chief, bug fixes

This finishes Chief's event, with all the necessary components for the post-game Mewtwo fight sorted as well. I added an event the Master Ball sets for modular monologue text, for improved immersion.

I have also fixed some bugs;
- Fixed the oft-reported walking in trees bug in the Forest tileset.
- Fixed the Oak's lab computer issue by just...removing the computer. I made the map symmetrical instead, feels a lot better to look at, at least for me. I think it was meant to have an event on it or something, but I couldn't find anything, felt like I was being gaslit.
- Hopefully fixed the issue with the border blocks going weird after saving and resetting, by making the tileset directly point to the gym one, which Oak is meant to use. I am not sure how that glitch happened for ViWalls.
- Fixed the Viridian Pre-Gym text scrolling issue.

I still cannot replicate the crash bugs that some people have been experiencing and don't see anything that could be causing it.

I also changed Trampel in Victory Road to Steelix, as mentioned by Gogocrafter.

data/maps/objects/RedsHouse2F.asm

@@ -3,8 +3,8 @@ RedsHouse2F_Object:
 
 	def_warp_events
 	warp_event  7,  1, REDS_HOUSE_1F, 3
-	;warp_event  5,  1, SILPH_GAUNTLET_7F, 1 ; - Test Chief 
-	warp_event  5,  1, SILPH_CO_11F, 2 ; - Test J&J, Omega, & Giovanni. To test the Omega refight, change to SHOW in hide/show data, and set warp ID to 1.
+	warp_event  5,  1, SILPH_GAUNTLET_7F, 1 ; - Test Chief 
+	;warp_event  5,  1, SILPH_CO_11F, 2 ; - Test J&J, Omega, & Giovanni. To test the Omega refight, change to SHOW in hide/show data, and set warp ID to 1.
 	;warp_event  5,  1, ROCKET_HIDEOUT_B4F, 2 ; - Test Giovanni 1
 	;warp_event  5,  1, MT_MOON_SQUARE, 1 ; - Test Shop, NPCs, and Crater
 	;warp_event  5,  1, CELESTE_HILL, 1 ; - Test GMolt