update solver params

yaml/solver.yaml

 minimizer: "LEVENBERG_MARQUARDT"
 interrupt_on_problem_change: false
-min_num_iterations: 4
-max_num_iterations: 20
-function_tolerance: 1e-7
-gradient_tolerance: 1e-9
+min_num_iterations: 5
+max_num_iterations: 500
+function_tolerance: 1e-10
+gradient_tolerance: 1e-10
 use_nonmonotonic_steps: false
-period: 0.1                     # note: this must be smaller (i.e. faster) than the KF period in processor_tracker_landmark_apriltag.yaml
-n_threads: 2
+period: 1                     # note: this must be smaller (i.e. faster) than the KF period in processor_tracker_landmark_apriltag.yaml
+n_threads: 8
 compute_cov: false
-verbose: 0
\ No newline at end of file
+cov_enum: 1 # compute all marginals
+cov_period: 1
+verbose: 1
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