Add Machine Provider ui parts

appengine/swarming/elements/res/imp/botpage/bot-page.html

 <!--
   Copyright 2016 The LUCI Authors. All rights reserved.
   Use of this source code is governed under the Apache License, Version 2.0
   that can be found in the LICENSE file.
 
   This in an HTML Import-able file that contains the definition
   of the following elements:
 
     <bot-page>
 
@@ skipping 213 matching lines @@
                 <td>First seen</td>
                 <td title="[[_bot.human_first_seen_ts]]">
                   [[_timeDiffApprox(_bot.first_seen_ts)]] ago
                 </td>
                 <td></td>
               </tr>
               <tr title="How the bot is authenticated by the server.">
                 <td>Authenticated as</td>
                 <td colspan=2>[[_bot.authenticated_as]]</td>
               </tr>
+              <template is="dom-if" if="[[_bot.lease_id]]">
+                <tr>
+                  <td>Machine Provider Lease ID</td>
+                  <td colspan=2>[[_bot.lease_id]]</td>

[smut, 2016/10/07 21:43:08]

Can you linkify this or do I need to include that info in the proto?

Basically the MP URL base needs to be extracted from luci-config (we already do
that and store it in the datastore) and joined with this lease_id to make a URL
to anchor here.

+                </tr>
+                <tr>
+                  <td>Machine Provider Lease Expires</td>
+                  <td colspan=2>[[_bot.human_lease_expiration_ts]]</td>
+                </tr>
+              </template>
             </table>
 
             <span class="title">State</span>
 
             <template is="dom-if" if="[[_not(_show_state)]]">
               <button on-click="_toggleState">
                 <iron-icon icon="icons:add-circle-outline"></iron-icon>
               </button>
             </template>
 
@@ skipping 346 matching lines @@
       },
 
       _toggleState: function() {
         this.set("_show_state", !this._show_state);
       }
 
     });
   })();
   </script>
 </dom-module>