fix(stepper) fix header text aligment (#1642)

Author: desig9stein

src/components/stepper/themes/step/step.base.scss

@@ -192,11 +192,17 @@
 }
 
 [part~='start'] {
+    --align-text: end;
+
     [part='text'] {
         order: -1;
     }
 }
 
+[part~='end'] {
+    --align-text: start;
+}
+
 [part~='start'],
 [part~='end'] {
     align-items: center;