Allow integrator to limit results in widget to certain languages.
If only one language is allowed, labels will be translated.
Otherwise default system language is used.
E.g. one record will be displayed in multiple languages, it would be
confusing to show him multiple times for each language.
Add TYPO3 extension for phpstan as many things would break within tests.
Relates: #15
Extract operating system from user agent and store it in database
record.
Another widget is added which displays the page views per operating
system.
An command is provided which will update existing data.
