fix(perception_replayer): initialize class variables to prevent crashes

[maxime-clem]

Description

Some uninitialized variables in the perception_replayer can cause crashes depending on the topics contained in the bag used.
This PR fixes these crashes.

Tests performed

Rosbag test.

Effects on system behavior

None.

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[codecov]

Codecov Report

Patch and project coverage have no change.

Comparison is base (a25cbe0) 15.92% compared to head (35f688f) 15.92%.
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #4944   +/-   ##
=======================================
  Coverage   15.92%   15.92%           
=======================================
  Files        1580     1580           
  Lines      109009   109009           
  Branches    33616    33616           
=======================================
  Hits        17361    17361           
  Misses      73034    73034           
  Partials    18614    18614           

Flag	Coverage Δ		*Carryforward flag
differential	0.00% <ø> (?)
total	15.92% <ø> (ø)		Carriedforward from a25cbe0

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