Add check for void @ApiOperation/@ApiResponse returntype and fix @ApiResponse response-type

[jfiala]

Description

The check for vendorExtensions.x-java-is-response-void implemented for jaxrs-spec in #4717 should be
backported to all Java languages.
Additionally, the currently used class for response is wrong (returnType is at the operation level, but the data type of the CodegenResponse should be used = baseType.

1. Add check for void at operation level

    @ApiOperation(value = "{{{summary}}}", notes = "{{{notes}}}"{{^vendorExtensions.x-java-is-response-void}}, response = {{{returnType}}}.class{{/vendorExtensions.x-java-is-response-void}}...

2. Change the response-Class to "baseType" and add check for void at @ApiResponse-level:

        @ApiResponse(code = {{{code}}}, message = "{{{message}}}"{{^vendorExtensions.x-java-is-response-void}}, response = {{{baseType}}}.class{{/vendorExtensions.x-java-is-response-void}}...

Languages to be updated:

• jaxrs-cxf-cdi
• jaxrs-spec [master]
• jaxrs-spec [2.3.0] (already up to date as of PR [Jaxrs-spec] Update jaxrs-spec to interface/impl pattern #4509 #4717 but only for release 2.3.0 as due to breaking change due to interface/impl generation)
• jaxrs (Jersey)
• jaxrs-cxf - PR [Jaxrs-cxf] add ApiResponse/s to operation #4718 #4920
• jaxrs-cxf-client
• jaxrs-resteasy
• java
• spring

Swagger-codegen version

2.2.2-SNAPSHOT

Related issues

Jaxrs-Spec issue #4509
PR 4717

[jfiala]

@wing328 after PR #4717 has been merged into master, I could update all other languages in one swipe/PR.

[jfiala]

I added step 1.) to AbstractJavaCodegen.java in PR #4823.