Battle Item Refactor Fixes

[AgustinGDLV]

I should've gotten to these sooner, but this fixes a few outstanding issues.

#2943: Revives are buggy in 1v2 Battles.

This was a simple fix. The battle script to send out the revived battler was changed to use BS_SCRIPTING and gBattleScripting.battler was set when an item required a revive animation. Originally, it was using BS_ATTACKER, meaning it would perform a send out animation on the battler that used the item.

#2967: Unable to cancel actions in a double battle after using an item.

I don't understand this fix if I'm being totally honest, but it works. In battle_controller_player.c, where B_ACTION_CANCEL_PARTNER_ACTION is supposed to be returned, I removed the Poke Ball check to return an item to the player's bag when cancelling an action after the first battler used an item. This was not meant to be the fix, but I couldn't find where to look next, and when doing some debug printing I noticed it was enough. Wonderful.

#2967: Bad item use battlestring.

This was a fix to BS_GetBattlerSide, which erroneously uses cmd->battler without passing it through GetBattlerForBattleScript. This means BS_ATTACKER will always be 1, so it will always print the enemy trainer string, which looks bugged for the player. There are other natives that seem to make this error as well.

Issue(s) that this PR fixes

Fixes #2943 and #2967.

Discord contact info

Agustin#1522

[AsparagusEduardo]

Looks good to me.