refactor tool scripts / folders

[stufraser1]

• app.R is 3700+ lines of code. This can be refactored into helpers, text blocks, reactive functions, etc.
• global.R is 390+ lines; already improved by section headings, but should be able to be refactored
• check LossSimulator/R folder for functions that are redundant (not used)
• check files in LossSimulator/supercededFiles can be safely deleted