Move the allowed formations from cmpIdentity to cmpUnitAI.
One needs UnitAI to be able to use a formation, so include the spec therein (to keep information close to where it is used).
Modders can change their templates with the following script: https://code.wildfiregames.com/P261.
Differential revision: https://code.wildfiregames.com/D4443
Comments by: @Stan
Idea accepted by: @wraitii
Fixes: #6399
git-svn-id: https://svn.wildfiregames.com/public/ps/trunk@26235 3db68df2-c116-0410-a063-a993310a9797