fix(albert): Keep straps even when there's no SA

The width of the straps was calculated by multiplying with the `sa`
value.
As a result, when the user asks to draft a pattern without SA, the
straps drop off the pattern.

I've also change the way the width is calculated. It used to be based
on a percentage option that was then multiplied by SA.
While technically that follows the best practice of using percentages,
it won't scale with the model unless you multiply it with a measurement.

packages/albert/config/index.js

@@ -34,6 +34,6 @@ export default {
     chestDepth: { pct: 22, min: 15, max: 90 },
     bibLength: { pct: 75, min: 0, max: 90 },
     bibWidth: { pct: 100, min: 50, max: 125 },
-    strapWidth: { pct: 750, min: 100, max: 1500 }
+    strapWidth: { pct: 60, min: 20, max: 100 }
   }
 }