Allow the .SubjectToGround of the Trajectory type to consider bridges

[DeathFishAtEase]

Set Trajectory.(Straight/Bombard).SubjectToGround=false to make the corresponding types of Trajectory pass through instead of colliding when encountering a bridge.

[phoboscn-bot]

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https://www.phoboscn.top/t/topic/396/1

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[DeathFishAtEase]

Tested by: https://www.phoboscn.top/t/topic/396/5

From west to east, respectively:

1. vanilla Arcing=true
2. Low Speed Straight, false(Trajectory.Speed= 50 & Trajectory.Straight.SubjectToGround=false)
3. Low Speed Straight, true (Trajectory.Speed= 50 & Trajectory.Straight.SubjectToGround=true )
4. High Speed Straight,false(Trajectory.Speed=200 & Trajectory.Straight.SubjectToGround=false)
5. High Speed Straight,true (Trajectory.Speed=200 & Trajectory.Straight.SubjectToGround=true )
6. Bombard, falseTrajectory.Bombard.SubjectToGround=false
7. Bombard, true Trajectory.Bombard.SubjectToGround=true