Epic: Move the services off Tomcat and onto Spring boot

[ac74475]

As this is an epic it will have a number of sub tasks associated with it and we don't want to merge this issue into develop until all such sub tasks are complete.

At the moment our micro-services have a much larger storage and memory footprint than is necessary due to the use of Tomcat as our web service framework. Instead it would be better to move to the current industry standard of Spring boot which provides many other benefits in terms of testability of code and adding the ability to drop new java classes into the data services and policy services so they can apply new types of policies without having to redeploy those services.

This change is likely to significantly change the performance of Palisade and will also make it easier to add some of the security features we will be looking to add in.