mock mode toggle to display a message for user?

[bzkrouse]

          Tested the following cases:

tfrmtbuilder(tfrmt = NULL, data = data_demog, mockmode = TRUE)
tfrmtbuilder(tfrmt = NULL, data = data_demog, mockmode = FALSE) 

tfrmtbuilder(tfrmt = tfrmt_demog, data = NULL, mockmode = TRUE)
tfrmtbuilder(tfrmt = tfrmt_demog, data = NULL, mockmode = FALSE)

tfrmtbuilder(tfrmt = tfrmt_demog, data = data_demog, mockmode = TRUE)
tfrmtbuilder(tfrmt = tfrmt_demog, data = data_demog, mockmode = FALSE)

No issues found :)

But perhaps we could consider adding a note somewhere (maybe in home tab?) that when mock mode is toggled on/off within the app, clicking the save and refresh buttons in edit tab will display mock placeholders/actual values. Not sure if it is currently clear?

Originally posted by @karima662 in #87 (review)