feat(NpcBots/bot_ai): Prevent tank/off-tank bots from automatically taunting from other tanks/off-tanks

[atrapalis]

Changes Proposed:

Tank/Off-tank bots currently use taunt on cooldown on any target from which they do not have aggro. This causes two issues in raids and dungeons:

• it makes crowd-control between multiple tanks very awkward as they keep taunting off each other
• it makes tanking as a player very awkward if there is a tank bot in the raid

The changes proposed here prevent tank/off-tank bots from taunting from other tanks/off-tanks as it is counter-intuitive to try and take threat from a creature which is already being tanked by someone else. This improves crowd/bot control in raids and dungeons.

This PR proposes changes to:

• Core (units, players, creatures, game systems).
• Scripts (bosses, spell scripts, creature scripts).
• Database (SAI, creatures, etc).

Tests Performed:

This PR has been:

• Tested in-game by the author.
• Tested in-game by other community members/someone else other than the author/has been live on production servers.
• This pull request requires further testing and may have edge cases to be tested.

I have been testing these changes for a while in a custom server without any issues.

[trickerer]

Bot off-tanks only taunt from other tanks in 2 cases:

• if the target is pointed off-tanking target and other tank is not an off-tank
• to save the other tank who is about to die
  Bot main tanks do about the same - only pointed main tanking target from off-tanks or almost dead tanks
  All this can be seen in bot_GridNotifiers.h where the selector is implemented. That's where any additional conditions belong
  There could be a problem with overlapping icons but I'm not sure right now.

The main problem with taunt is you can't set player as a tank unless in raid or LFG group so bot tanks will constantly try to grab everything from you trying to do the tanking.

These changes as they are aren't needed. Check FarTauntUnitCheck class operator for existing conditions.

[atrapalis]

Thanks for reviewing this! Let me do some more tests to see if anything has changed since I first tested this because it was a long time ago. I know about the requirement to set players as a raid/lfg tank and I took that into account when I tested this originally.

[atrapalis]

@trickerer I just did some more testing and you are right. I believe this commit 8eef51c makes my changes redundant. The logic is equivalent and it looks like the results are the same.

I must have first worked on my "hack" before this logic was implemented in FarTauntUnitCheck. Will close this pull request now.