change environment for .RData objects

[cschwem2er]

As of now, all objects from the .RData input file are loaded into the global R environment. It would be better if user would find their environment untouched after stopping the app. There needs to be a way to find the objects in another non-global environment when loading the data, but all attempts so far were not successful.

Related code starts here:
https://github.com/methodds/stminsights/blob/79d883d88f3b7a66a42bbe5fa71f2a3f0d4194a8/inst/app/app.R#L534

[cschwem2er]

Closed due to inactivity