[Misc] Add all xwiki system properties as custom data in GE + tag some of them
[Misc] Add all xwiki system properties as custom data in GE + tag some of them

- Replace project.properties by System.getProperties()/System.getProperty()
- Use findAll instead of find to loop over all the properties

xwiki/xwiki-platform,xwiki/xwiki-platform,xwiki/xwiki-platform,xwiki/xwiki-platform,xwiki/xwiki-platform