Flexibly generate and control one and multi parameters forest plots

• ui improvements and controls for the new arguments
• added x/y_facet_text_vjust/hjust arguments for the facets x/y text hjust/vjust
• added xy_facet_text_bold argument to control facets text face
• added facet_spacing argument to control facets spacing
• added facet_labeller argument (function only not in the shiny app)
• added strip_outline argument to allow the removal of strip.background
• added show_yaxis_gridlines and show_xaxis_gridlines arguments to be able to remove axes grid lines
• added show_ref_value and ref_value_col arguments for better controls on the ref line
• added plot_margin argument (controls plot margins)
• added table_margin argument (controls table margins)
• added legend_margin argument (controls legend margins)
• added parse_xlabel and parse_ylabel arguments to parse xlabel, ylabel
• added table_panel_border argument to allow the removal of panel.border of the table plot
• added reserve_table_xaxis_label argument to allow alignment of switched strips
• added legend_position argument to control the legend position
• added legend_ncol_interval argument to control number of columns of the interval legend
• added legend_ncol_shape argument to conrol number of columns of the shape legend
• added vignette on pediatric multivariate covariate simulations and temporarily removed the pk and pkpd ones