Fixed module-info formatting in eclipse-jdt.

[fvgh]

Since JDT Core 3.13, the module-info formatting is distinguished by filename.
This PR still uses spotless-eclipse-base 3.5 and therefore requires JVM 11.

[fvgh]

@nedtwigg
You are quite relaxed about code style when it comes to the _ext projects.
I would like your opinion on the backward compatibility.
I quickly checked the compliance with JDT core 3.13. It works fine. So we could provide backward compatible patches by releasing two versions (4.8.1 for JVM 8 and old base version / 4.9.0 for JVM 11).

On the other hand, nobody ever complained and I myslef are not planing to use Java modules without using at least Java 11.

Let me know what you prefer.

[nedtwigg]

LGTM.

[nedtwigg]

Published in plugin-gradle 5.17.0 and plugin-maven 2.17.1