Fixing warnings

[danny-waughman]

DL-3885

This service had over 300 warnings and required a lot of minor changes. This included:

• Removing various imports & parameters

• Using dependency injections in the twirl templates to refer so certain layouts, which in turn required some changes to be made to the controllers and unit tests

Checklist

• [x] I've made every effort to commit high quality, clean code and I have executed relevant static analyses to be sure
• [x] I've included appropriate tests with any code I've added (Unit, Integration, Acceptance etc.)
• [x] I've executed the acceptance test pack locally to ensure there are no functional regressions
• [ ] I've added my code using logical, atomic commits, squashing as appropriate - including the JIRA issue number in the commit message
• [x] I've run a dependency check to ensure all dependencies are up to date

[alijy]

Injection shouldn't be used in unit tests. Any test class with injection is ignored. I've added comments on a couple of them, but it is extended to any test class with injection. Currently only 73 out of 174 suits (666/1851 tests) are being executed.