Add ICD-10 and OPCS4 breakdowns to Shiny App

[milanwiedemann]

Following #94 we can add breakdowns to the Shiny App. There are three different types of breakdowns we added to the data:

• Position of diagnosis (2 breakdowns)
• Gender (3 breakdowns)
• Age (24 breakdowns, for simplicity we should aggregate these into 6 groups so it's easier to visualise in the space we have available in the app)

We could add a checkbox and two dropdown boxes to the trends over time table:

[milanwiedemann]

An alternative could be to add a Select breakdowns tab next to select data (see orange box)