Python3: PAL

- files renamed:
  - utils.py --> pal_utils.py
  - errors.py --> pal_errors.py
- functions/methods renamed:
  - plot_service_density_reconf_box_name --> plot_nf_reconf_box_name
  - plot_performance_box_name --> plot_perf_box_name
  - plot_latency_error_bars_name --> plot_lat_err_bars_name
  - plot_throughput_speedup_analysis_name --> plot_tsa_name
  - plot_service_density_heatmap --> plot_nf_heatmap
  - table_performance_comparison --> table_perf_comparison
  - table_performance_comparison_nic --> table_perf_comparison_nic
  - table_performance_trending_dashboard_html --> table_perf_trending_dash_html

- functions/methods removed:
  - plot_service_density_heatmap_compare
  - plot_throughput_speedup_analysis
  - plot_latency_error_bars
  - plot_soak_boxes
  - plot_soak_bars

Change-Id: Icddc01d3ccb451abb92b9e5d912b642d01866033
Signed-off-by: Tibor Frank <tifrank@cisco.com>