Improve enemy obstacle avoidance

[SorraTheOrc]

Update: Item 2 has been done and this seems to have improved enemy behaviour a little. Moving back to backlog while we establish how much of the other items remain.

1. Enemies still occasionally passing through buildings

Most commonly it is the stingers, but also seen Saucers and Shielded Core doing it.

• [ ] For small enemies it may be enough to increase avoidance range
• [ ] Does speed have an impact here?
• [ ] If there are too many enemies trying to get through a gap have some go in a different direction
• [ ] don't get caught on the trees

2. The enemies stutter when avoiding a wall. It goes like this:Most easily reproduced with a Shielded Core trying to get down an alley

• Detect wall forward/right
• Turn left
• No wall detected
• Turn right back to desired path
• Back to start

What we need to do is flag when we are avoiding an obstacle on the right/left and test for it, only going back to the original path once we are past the obstacle:

• Detect wall forward/right
• Turn left
• Test for wall behind right
• if present stay on current path
• if not present, turn right back to desired path

[SorraTheOrc]

In order to test for the second item (narrow passageways) we need to:

-[x] build a test level that will force the enemies down an ally see `Assets/_Dev/Resources/Levels/Specific Scenario Levels/Level 3x2 Narrow Passageway.asset -[x] adjust avoidance logic to prevent oscillation in the passageway