[battle_engine] Explosion, Mind Blown, Multihit-absorb interaction, Mega-related fixes.

[kleeenexfeu]

I would have normally done this in two separate PR, but because the first PR removes the need of a vanilla battlescript command and that I recycled it in what would have been the second PR, I choose to do all at once.

This PR needs #1676 to be merged, because it accounts for parental bond for Mind blown.

Part 1:
-Fixes multi-hit moves ignoring Volt Absorb, Storm Drain, etc, after the first it.
-Fixes volt absorb (and other absorbing abilities) preventing other mon on the field from being damaged by a galvanized explosion.
-Same fix for mind blown, but with flash fire.
-Explosion can now be used when no target are available, as stated in bulbapedia. The move will be used, the animation played, the user KOed, but it will have no effect.
-Effectively removes the need of faintifabilitynotdamp battlescript command. It can freely be renamed and used for something else, and its code removed. Let me know if I have to remove it!
Basically, the only reason explosion wouldn't faint the user is if the move is not used at all (confusion, etc.) or if damp is active on the field. Same thing applied for mind blown, except for the no-targets-available case.
-Fixes damp string sometimes confusing which mon's ability to display by adding a new case in the placeholder ability decoder and updating the charmap.txt.

Currently, explosion doesn't trigger eject button on a target. I didn't find any reliable source to confirm whether or not it's the right behavior. This can easily be modded by either changing the check where I left a comment in the MOVEEND_EJECT_BUTTON section, or by just swapping the order of MOVEEND_EJECT_BUTTON and the newly added MOVEEND_KO_USER in the defines.
This can be closed when this PR is merged.

After it is merged, the new moveend case will have to go either before or after eject button case, depending on the modern games' mechanics.

Part 2:
-Mega Evolution happens now before Pokemon use their move, but after pokémon switch out, if any.
-Accounts for pursuit edge case : The pursuit user will mega evolve, attack the switching-out mon, and will be done for the turn.
-Mega Evolution will now happen according to the turn order, and not going from battlerId 0 to (gBattlerCount - 1). This change is very important for mons gaining weather abilities upon mega evolving, among other things.
-isWishMegaEvo has been expanded to an array of 4 booleans, to fix the bug where the fervent wish string would be used for the AI even though it was performing a regular mega evolution.
-Refactors the battlescript to use call instead of duplicate scripts.
-Use the old command faintifabilitynotdamp which has be renamed and recoded after the revamp of explosion.
-Makes the recalculation of the turn after mega evolution a tiny easier to read.
-Addresses everything mentionned in this issue and possibly more, as seen here. Although the last one was fixed in a reverted commit, I explain in the code why a few lines should be changed.
This PR does NOT update pursuit to its latest behavior.

[kleeenexfeu]

The suggested changes in this file until this point should be done in my opinion, but I wouldn't mind someone taking a good look at them.

From here the changes just fix a bug with the fervent wish string.

[AsparagusEduardo]

It's not compiling

[kleeenexfeu]

Same as before lol, it requires the parental bond PR :p
Mentionned on the top of my comment

[AsparagusEduardo]

Same as before lol, it requires the parental bond PR :p Mentionned on the top of my comment

Sorry, I didn't fully read the PR because I'm on and off with the pret merge ^^;
I'll leave this PR as a Draft in the meantime.

[AsparagusEduardo]

Closing this for now, as the required PR is in review purgatory and after such a long time it'll be better to tackle this in a new PR.