Cleanup implementation of REST views

- specify return type if possible
- remove unnecessary throw declarations
- convert some of the thrown exceptions to RestExceptions
- do not throw Exception but specific exceptions
- sort throw declarations (first RestExceptions, then other
  exceptions)

Having explicit return types and exceptions makes it easier to
programatically invoke the REST views, e.g. if a plugin wants to add a
REST view that wraps a Gerrit core REST view.

Change-Id: I5c59553b6cfad457f7ec037cceb08936247bf8e8
Signed-off-by: Edwin Kempin <edwin.kempin@sap.com>

gerrit-server/src/main/java/com/google/gerrit/server/account/StarredChanges.java

@@ -157,7 +157,7 @@ class StarredChanges implements
 
     @Override
     public Response<?> apply(AccountResource.StarredChange rsrc, EmptyInput in)
-        throws AuthException, OrmException {
+        throws AuthException {
       if (self.get() != rsrc.getUser()) {
         throw new AuthException("not allowed update starred changes");
       }