Polish Examples

There are multiple small issues in the Examples:

- Name of page and entry in navigation are mostly inconsistent
- The max length of 5 does not make any sense in the array control example. It seems weird that the example contains initial invalid data
- Categorization example is currently broken. It only renders ```No applicable renderer found.```
- Inferring a UI schema and Inferring both schemata are partially broken. For one of the elements they also render ```No applicable renderer found.```
- The star renderer in custom control example does not properly showcase how a good custom renderer should look like. A label (for example Rating) is missing. Also the cursor on the star renderer looks weird.

Also see eclipsesource/jsonforms#853 and eclipsesource/jsonforms#854