feat: suppress warning/error of the empty predicted trajectory by MPC

[takayuki5168]

Description

The empty predicted trajectory is intended when the MPC is in an emergency such as too large deviation from the planning trajectory.
Based on this specification, I changed the logger level of the error/warn messages for the predicted trajectory since they fill the terminal.

Related links

How was this PR tested?

Notes for reviewers

None.

Interface changes

None.

Effects on system behavior

None.

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[codecov]

Codecov Report

Attention: Patch coverage is 0% with 2 lines in your changes missing coverage. Please review.

Project coverage is 29.65%. Comparing base (b4603fd) to head (adcac77).
Report is 44 commits behind head on main.

Files with missing lines	Patch %	Lines
...toware_control_validator/src/control_validator.cpp	0.00%	1 Missing ⚠️
...rture_checker_node/lane_departure_checker_node.cpp	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #9373      +/-   ##
==========================================
- Coverage   29.66%   29.65%   -0.01%     
==========================================
  Files        1338     1344       +6     
  Lines      103204   103249      +45     
  Branches    40216    40219       +3     
==========================================
+ Hits        30611    30615       +4     
- Misses      69638    69679      +41     
  Partials     2955     2955              

Flag	Coverage Δ		*Carryforward flag
differential	22.44% <0.00%> (?)
total	29.66% <ø> (+<0.01%)	⬆️	Carriedforward from b4603fd

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