[z2088] Change behaviour of text selection for gossip menus

This way the behaviour will be well defined in case multiple conditions match.
Now the text with the highest condition-id will be taken.

(based on commit [12127] - f75ce40)

(based on commit [s1706] - f9eecdb)
[z2089] Remove unused argument from OutdoorPvP::HandlePlayerKillInsideArea

(based on commit [12132] - 7bd3172)

(based on commit [s1708] - a8e789c)
[z2090] Remove unneeded InBattleGround() as it is already checked by GetBattleGround()

Also call OutdoorPvP handlers before instance script ones

(based on commit [12133] - 760c6eb)

(based on commit [s1709] - 8005ed6)
[z2091] Add HandleEvent and HandleGameObjectCreate to battleground class

(based on commit [12134] - 1ae2658)

(based on commit [s1710] - 041310c)
[z2092] Prevent saving/loading/init capture points in instances

Reason for this are:
1) We don't want them saved/loaded between bg games
2) Saving cp slider is done by go id and would not work for instances
3) There are visual-only capture points in bg (eots)
4) It would be possible to only enable the capture points on bg start

TODO: Move this to OutdoorPvP base class

(based on commit [12135] - 536175e)

(based on commit [s1792] - db83495)
[z2093] Merge Player::CanUseOutdoorCapturePoint into Player::CanUseCapturePoint

(based on commit [12137] - f1d006b)

(based on commit [s1712] - 53b1479)