refactor(start_planner): remove unused parameters in start planner module

[kyoichi-sugahara]

Description

• remove unused param
  • deceleration_interval
  • arc_path_interval
  • th_turn_signal_on_lateral_offset
  • intersection_search_length
  • length_ratio_for_turn_signal_deactivation_near_intersection

related with the PR

Tests performed

run psim

Effects on system behavior

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