[legend] let legend size overflow for arbitrary sizing

The overflow check for the legend is not super useful. If one wishes
to move the legend position to somewhere else (e.g. in a facet plot
with 3 plots there's empty space at the bottom right), it makes sense
to allow the plot range to fill the full plot, which depending on
inputs might cause an overflow in the layout logic.

Author: Vindaar

src/ggplotnim.nim

@@ -1644,7 +1644,8 @@ proc genDiscreteLegend(view: var Viewport,
              colWidths = @[quant(width, ukCentimeter),
                            quant(0.3 * bScale, ukCentimeter),
                            quant(0.0, ukRelative)],
-             rowHeights = rH)
+             rowHeights = rH,
+             ignoreOverflow = true)
   # iterate only over added children, skip first, because we actual legend first
   var j = 0
 
@@ -1694,7 +1695,8 @@ proc genContinuousLegend(view: var Viewport,
                          geomKind: GeomKind) =
   case cat.scKind
   of scSize:
-    view.layout(1, rows = 5 + 1)
+    view.layout(1, rows = 5 + 1,
+                ignoreOverflow = true)
   of scColor, scFillColor:
     # create following legend layout
     # _______________________
@@ -1713,13 +1715,15 @@ proc genContinuousLegend(view: var Viewport,
                 colWidths = @[quant(0.5 * bScale, ukCentimeter), # for space to plot
                               quant(0.0, ukRelative)], # for legend. incl header
                 rowHeights = @[quant(legendHeaderHeight, ukCentimeter), # for header
-                               quant(legendHeight, ukCentimeter)]) # for act. legend
+                               quant(legendHeight, ukCentimeter)],
+                ignoreOverflow = true) # for act. legend
     var legView = view[3] # bottom right
     legView.yScale = cat.dataScale
     let width = theme.continuousLegendWidth.get(1.0)
     legView.layout(3, 1, colWidths = @[quant(width * bScale, ukCentimeter),
                                        quant(0.5 * bScale, ukCentimeter),
-                                       quant(0.0, ukRelative)])
+                                       quant(0.0, ukRelative)],
+                   ignoreOverflow = true)
     var legGrad = legView[0]
     # add markers
     let markers = legGrad.generateLegendMarkers(cat, theme, geomKind)