Epic: {T346285}
== Background
In {T350495}, we deployed the latest version of the JS client library. We can now migrate the WikiLambda instrumentation to use core interaction events.
Since the the WikiLambda instrumentation has a lot of instrumentation-specific (domain-specific?) custom data, this will provide a good case study in creating and using a new schema that extends the core interaction event schema with the JS client library.
== AC
[] Wherever possible, the data logged by [[ https://codesearch.wmcloud.org/search/?q=dispatchEvent%5C%28&files=resources%5C%2Fext%5C.&excludeFiles=&repos=Extension%3AWikiLambda | the existing instrument ]] is mapped to the `{ action, action_subtype, action_source, action_context }` 4-tuple
[] Repeated fields are identified and a schema fragment is created
** e.g. `/fragment/mediawiki/wikilambda/common/1.0.0`
[] If a schema fragment is needed (it probably is), then a new schema is created
** e.g. `/analytics/mediawiki/product_metrics/wikilambda/ui_actions/1.0.0`
[] The instrument is updated to use the above (keeping the previous one for now)
[] The new stream configuration is added (keeping the previous one for now)
== Notes
1. Example mappings that @sfaci and I worked through on 24/1/15:
<table>
<tr>
<th>Event name</th>
<th>Custom data</th>
<th>Mapping</th>
</tr>
<tr>
<td>`wf.ui.editFunction.load`</td>
<td>
* `isnewzobject`
* `zobjectid`
* `zlang`
</td>
<td>
* `action=edit_function`
* `action_subtype=create` or `=edit` depending on `$isnewzobject`
* `action_source=$zobjectid`
* `action_context=$zlang`
</td>
</table>