Refactor non-time trend handling and improve residuals plotting

- Removed unused variable `_EIV_TRIGGERED` from logger.
- Updated `_compute_nontime_trend` to return a dictionary of components instead of a single result.
- Introduced `panel_nontime_residuals.py` to render PDF pages showing partial residuals for non-time components.
- Modified `render_panel_overlay` to simplify y-label handling by removing non-time trend checks.
- Deleted `panel_raw.py` as it is no longer needed.
- Enhanced `generate_report` to include non-time component partial residuals for both individual visits and overall.
- Adjusted `prepare_plot_data` to handle non-time trends more effectively, including mapping component names to their X-variables.
- Updated plotting functions to accommodate changes in data structures for non-time trends.
- Improved figure layout management by removing raw data panel references and adjusting axes accordingly.