* Remove method `getId()` from all lessons as it defaults to the class name
* remove clean up endpoint
* remove unused class `RequestParameter`
* remove unused class `PluginLoadingFailure`
* Move `CourseConfiguration` to lesson package
* Add more content around the lesson template lesson and make it visible as a lesson in WebGoat
* Remove explicit invocation `trackProgress()` inside WebGoat framework so assignments only need to return an `AttackResult`
* Put original solution back as well for SQL string injection
* review comments
* Add
* Remove Guava dependency from WebGoat
* Add Checkstyle to the project with very basic standards so we have a
style across lessons. It does not interfere with basic Intellij formatting
- Now using Spring Boot for classloading, this way local development does not need to restart the complete server
- Fixed all kinds of dependencies on the names of the lessons necessary to keep in mind during the creation of a lesson.
- Simplied loading of resources, by adding resource mappings in MvcConfig.
- Refactored plugin loading, now only one class is left for loading the lessons.
Squashing and merging ...
* Each assigment should have the options to have its own set of hints #278
* Updating lessons due to changes from #278
* Enable i18n client side #312
* IDOR move hints to assignment and enable i18n #312
