Add the reason phrase back to responses from the AJP connector

The sendReasonPhrase method was removed and the reason phrase can no longer be enabled. Some users systems require the reason phrase for health checks, etc. The removal of the reason phrase is preventing some users' adoption of Tomcat 9.0.x as external systems need to be modified to cope with the change. This issue will allow users to utilize the reason phrase when using the AJP connector configuration.

Note: This change will not be included in the JWS 6.0 release, so users that require the reason phrase should alter their health checks, etc before migrating to JWS 6+.