[FIX] web: speedup basic_model._updateRecordsData

Speedup basic_model._updateRecordsData for
many2many fields such as fetchmail.server.message_ids
and mail_channel.channel_message_ids.

Calling _.findWhere(values) inside two nested _.each
calls can be quite slow when the number of values
is big.

Remove the call to _.findWhere by first
creating a Map res_id -> data and then calling
Map.get to retrieve the data for a given res_id
when making a DataPoint

opw-2701170

closes odoo/odoo#82540

X-original-commit: aaf653e744c846d4c399498ea38e358ddee80d4a
Signed-off-by: Aaron Bohy (aab) <aab@odoo.com>

addons/web/static/src/legacy/js/views/basic/basic_model.js

@@ -5211,6 +5211,7 @@ var BasicModel = AbstractModel.extend({
         var fieldsInfo = view ? view.fieldsInfo : fieldInfo.fieldsInfo;
         var fields = view ? view.fields : fieldInfo.relatedFields;
         var viewType = view ? view.type : fieldInfo.viewType;
+        var id2Values = new Map(values.map((value) => [value.id, value]))
 
         _.each(records, function (record) {
             var x2mList = self.localData[record.data[fieldName]];
@@ -5218,7 +5219,7 @@ var BasicModel = AbstractModel.extend({
             _.each(x2mList.res_ids, function (res_id) {
                 var dataPoint = self._makeDataPoint({
                     modelName: field.relation,
-                    data: _.findWhere(values, {id: res_id}),
+                    data: id2Values.get(res_id),
                     fields: fields,
                     fieldsInfo: fieldsInfo,
                     parentID: x2mList.id,