Resolve "PDF Editor doesn't load"

Closes #449 (closed)

Seems to be related to this issue filed last month: https://community.adobe.com/t5/acrobat-services-api-discussions/problem-pdf-embed-api-dc-core-loaded-twice/td-p/13938274

No concrete solution proposed by the devs other than this workaround provided by another user. This probably has something to do with us mounting the page more than once due to data coming in but we've never had this issue with the viewer before.