server.servlet.contextPath set

The caches.size metric is not available for every cache implementation.
If the metric is not available the ui should still show hits and misses.
This commit ignores errors for the cache size and will do no further
requests for this metric after an error occurred.

fixes #756

also fix table styling in httptraces, auditevents and sessions

fixes #728

closes #697

The system.load.average.1m metric is not available on all platforms.
Therefore we ignore errors from fetching it.

closes #697

If the build version of the instance is present in the metadata it's now
also considered and the version is now a attribute on the instance
itself. So when using non-boot application they can provide it via the
registration metadata.

this ensures that the application name gets escaped

closes #313

unecessary scss sections removed
no type for errors props