Provide more hover info in certain cases

[vasiltabakov]

Hovering "OK" shows the type and name of the constant:

It would be much better if it also showed its value, the definition of the constant in this case is as follows:
public static final int OK = 0;

so it would be much better if the tooltip showed:
int OK = 0

at least for primitive types and maybe for strings which could get truncated if too long.

[fbricon]

Indeed, JDT UI supports that feature https://www.eclipse.org/eclipse/news/4.11/jdt.php#default-constant-values
Hopefully it should be easy to implement