Add DeferredResult to SpringRestController

[godmarch33]

1 Add DefferedResult to SpringRestController
2 Add test for SpringControllerDefferedResult
3 update tests naming files for async type
4 apply formatter plugin

[stojsavljevic]

Hi,

thanks for the PR.
Something I noticed:

• as far as I can see, changes in pom.xml are not required
• code in BaseControllerDecoratorAsyncDeferredResult.java.txt doesn't compile since interface specifies DeferredResult<ResponseEntity<NamedResponseType>> as return type for getNamedResponseTypeById method and implementation returns DeferredResult<NamedResponseType>; this probably means some additional coding
• I would like that isDeferredResult() check in rules comes after other checks like isCallableResponse()
• please drop all formatting changes like javadoc in SpringControllerDecoratorRule.java for example
• please fix javadoc in newly generated files; you don't have to provide an example but describe what class does, add proper @author and @since tags etc

[stojsavljevic]

Support for DeferredResult is added as part of #257.
Closing this one.