Core/Movement: follower will check target's vehicle for follow motion

[sanctum32]

In this commit i added basic checks which will check target's current vehicle movement flags to determine if it moved. By default if if player is on vehicle, follow units will not follow player I honestly unsure if these changes are acceptable by current standarts.

Changes proposed:

• Made changes in IsTargetMoving function which will perform follow target vehicle checks to allow follow motion to continue

Issues addressed: Fixes #

Tests performed: (Does it build, tested in-game, etc)

• Build (windows 11 x64 / Fedora 38 x64)
• Mainly tested on quest https://www.wowhead.com/quest=14416/the-hungry-ettin

Known issues and TODO list:

• [ ]
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[sanctum32]

Just want to add note - some movable vehicles places ROOT movement flag on passenger, so technically base target is not moving for follower while vehicle is moving. In base, i'm unsure, this probably needs distance checks probably