Improve SpringMvcEndpointDetector by detecting new RequestMapping annotation shortcuts

[ptamarit]

Spring 4.3 introduced new annotation shortcuts for @RequestMapping.
For instance, @GetMapping is a composed annotation that acts as a shortcut for @RequestMapping(method = RequestMethod.GET).

The full list of new shortcut annotations is:

• @GetMapping
• @PostMapping
• @PutMapping
• @DeleteMapping
• @PatchMapping

This pull request improves SpringMvcEndpointDetector by detecting these new annotations.

Some remarks regarding this pull request:

• I modified the English message, but I don't have the necessary skills to modify the corresponding Japanese one.
• Instead of having a hardcoded list of annotations, a more future-proof solutions would be to rely on the annotations hierarchy. Indeed, @GetMapping is annotated with @RequestMapping, @RequestMapping is annotated with @Mapping, and @Mapping is described as a "Meta annotation that indicates a web mapping annotation". However, I didn't find a way of going up one annotation's hierarchy with FindBugs.