JBIDE-17177 - Wrong @NameBinding quick fix for a @Target annotation

Fixing the quick fix applied
Refactoring the code for quickfixes
Including Java Proposals when missing values (with or without parenthesis)
Adding JUnit tests to check the quckfixes proposals and their application
Also adding a content assist proposal for the @HttpMethod annotation value, based on the annotation name.

Also fixed JBIDE-17307 Missing label and broken link for JAX-RS problem severity configuration