tune opcodes / add placeholder safety params

[justinIRBT]

Description

Adjust parameters to achieve behavior more similar to robot with shorter overall range, directional sensor longer range than omni, and smaller omni FOV to account for create3 mount plate on top.

Fixes # (issue).

https://github.com/iRobotEducation/create3_sim/issues/93

Type of change

• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)

How Has This Been Tested?

joysticked around sim and verified ir_opcode topic printed expected values at different positions relative to the dock

Checklist

• [x] I have performed a self-review of my own code
• [x] I have commented my code, particularly in hard-to-understand areas
• [ ] I have made corresponding changes to the documentation

[justinIRBT]

@rjcausarano Just wanted to complement you on the way you represented the sensors, I was happy to discover I wouldn't have to do anything other than tune numbers to get the behavior I wanted.