Generating a report is saved on disk instead of in blob can cause problems for non-sticky load balanced environment

Description

The problem is when generating a report specificly the call

https://www.abc.se/EPiServer/EPiServer.Forms.UI/DataExporting/PrepareExport

It saves the file to the disk using Path.GetTempPath() eg the systems temp path. That means that the callback in a non sticky load balanced enviroment most likely will hit another instance when trying to get the file.

A good option for where to save it is in the blob storage if there is one configured.

In order to use Azure blob storate
1. Add config to web.config

<episerver.framework>
  <blob defaultProvider="azureblobs">
      <providers>
        <add name="azureblobs" type="EPiServer.Azure.Blobs.AzureBlobProvider,EPiServer.Azure"
              connectionStringName="EPiServerAzureBlobs" container="mycontainer"/>
      </providers>
  </blob>
...

2. In Forms.config add setting to use the provider

<episerverforms dataExportBlobProviderName="azureblobs">