erp5_document_scanner: upload images asynchronously to improve the usability

XXX
Allow to show previously uploaded image.
Allow to delete or retry uploading.

Form submittion only send the active process informations.

bt5/erp5_document_scanner/PathTemplateItem/web_page_module/rjs_gadget_document_scanner_js.xml

@@ -244,7 +244,7 @@
                   </item>
                   <item>
                       <key> <string>serial</string> </key>
-                      <value> <string>981.21579.36694.13363</string> </value>
+                      <value> <string>981.21983.29656.41591</string> </value>
                   </item>
                   <item>
                       <key> <string>state</string> </key>
@@ -262,7 +262,7 @@
                           </tuple>
                           <state>
                             <tuple>
-                              <float>1579684586.42</float>
+                              <float>1579708838.71</float>
                               <string>UTC</string>
                             </tuple>
                           </state>