Migrate data import from global.r to server.r

[bernardsilenou]

Feature Description

When sormas db is empty, the app breaks because there is no data to analyse

Problem Description

Allow app to launch even there is no data in sormas db

Proposed Change

• migrate load data to server.r
• update all UI elements that depends on imported data with a default data
• refs: https://rdrr.io/cran/shinyWidgets/man/updatePickerInput.html

  Possible Alternatives

Additional Information

[jwijffels]

@bernardsilenou I've created a merge request to fix this at https://github.com/hzi-braunschweig/SORMAS-Stats-next-gen/pull/135

[jwijffels]

• pull request https://github.com/hzi-braunschweig/SORMAS-Stats-next-gen/pull/136 which loads the app without having access to the DB

[jwijffels]

The 2 pull requests moved the data loading to the server side except the fixed shapefiles Everything which fails due to either data connectivity or missing data in the database is now shown as an error message at the startup of the app. This involves all data loading code at https://github.com/hzi-braunschweig/SORMAS-Stats-next-gen/blob/development/sormas-stats-shinyapp/sormas-stats-app/server.R#L6:L127