Fix bug in measurement area decorator.

Make input validation accept "m²" and "mm²"

src/bonsai/bonsai/bim/module/model/decorator.py

@@ -749,6 +749,7 @@ class PolylineDecorator:
 
         # Area highlight
         if polyline_data:
+            print("A", polyline_data.area)
             _, area = tool.Polyline.validate_input(polyline_data.area, "AREA")
             if area:
                 if float(area) > 0:

src/bonsai/bonsai/tool/polyline.py

@@ -419,7 +419,7 @@ class Polyline(bonsai.core.tool.Polyline):
 
         FORMULA: "="
 
-        metric: NUMBER "mm"? "m"? "°"?
+        metric: NUMBER "mm²"? "m²"? "mm"? "m"? "°"?
 
         expr: (ADD | SUB | MUL | DIV) dim