Set uri encoding to UTF-8 by default for Tomcat

This commit introduces an extra `server.tomcat.uri-encoding` property used to configure the URI encoding for the embedded tomcat container.

This defaults to `UTF-8` instead of what tomcat uses by default (i.e. `ISO-8859-1`). Note that Jetty uses 'UTF-8' by default but can only be customized through the use of a system property so this new setting only applies for Tomcat.

Fixes gh-540