Plugins cannot opt out of Struts request filtering

Issue Summary

The Struts request filter consumes the incoming request stream which prevents it from being consumed again.

Currently only /rest/* is exempt from Struts request filtering - however plugins may only register servlets which map to /plugins/servlet/.

Note: This was not an issue in Confluence 7 as WebWork was a mapped Servlet as opposed to a filter.

Steps to Reproduce

1. Create a servlet and attempt to consume multipart request stream

Expected Results

Read request stream

Actual Results

Unreadable

Workaround

N/A