Add flowsensor prototype, add canbus to backplane

rust/src_webpack/src/tankview.html

@@ -48,6 +48,10 @@
   <div class="tankkey">Full at %</div>
   <input class="tankvalue" type="number" min="0" max="100" id="tank_full_percent">
 </div>
+<div class="flexcontainer">
+  <div class="tankkey">Flow Sensor ml per pulse</div>
+  <input class="tankvalue" type="number" min="0" max="1000" step="0.01" id="ml_per_pulse">
+</div>
 <button id="tank_update">Update Tank</button>
 
 
@@ -82,4 +86,4 @@
 <div class="flexcontainer">
   <div class="tankkey">Warn Level</div>
   <label class="tankvalue"  id="tank_measure_warnlevel"></label>
-</div>
+</div>