fix(covertPathData): add test case for #1927

Author: SethFalco

test/plugins/convertPathData.36.svg.txt

@@ -0,0 +1,15 @@
+Should process/optimize q correctly even if useless commands in between.
+
+See: https://github.com/svg/svgo/issues/1926
+
+===
+
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1 20">
+  <path d="M-6.3 9.9q.7-4.5.2-5-.5-.5-1.5-.5l0 0q-.4 0-2 .3"/>
+</svg>
+
+@@@
+
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1 20">
+    <path d="M-6.3 9.9q.7-4.5.2-5t-1.5-.5q-.4 0-2 .3"/>
+</svg>