Use random password for in-memory H2 database

[sleberknight]

Currently we use a hard-coded password (the horror) for in-memory H2 databases. Even though this should not be a problem, since the database is in-memory and is only accessible from within the JVM that launched it, Sonar is complaining that our "rotten tomatoes" password is compromised. 🍅

Of course, if someone is already inside a server, then there are probably much bigger problems than them getting into the in-memory database for a service which contains information about application errors that have occurred! 🤣

Anyway, since it's easy enough to generate a random password for the in-memory H2 database, let's do that and make Sonar happy. 👍

Apache Commons Lang has a lovely RandomStringUtils class that we can use to generate strings of a specific length with random (well, pseudo-random) characters.