In EAD bulk export remove the classification dropdown

[mickeroo]

We want to be able to export all of the records in EAD format and the current exporter prompts for classification. We don't care about that so remove it so that all will be exported.

[mickeroo]

Unfortunately, the time it takes Archon to export all 1200+ EADs exceeds the server's timeout limits. We should be able to convert this task to a job that can be run standalone, but at the moment we don't have the development resources to do it. We should look at this as a post-launch enhancement as exporting can still be done by classification.