Update import tab "Option C: Upload dataset"

[cristinamullin]

Is your feature request related to a problem? Please describe.

A shiny app user may want to upload their own data using "Option C: Upload dataset" on the import tab. This option is not fully fleshed out and needs to be updated and tested with example datasets.

When a dataset is uploaded, we need to check that all TADA required columns are included in dataset and we need to run autoclean on the dataset on import. On import, at least the following two functions should be run:

1. TADA_CheckRequiredFields()
2. TADA_AutoClean()

Note: The package function TADA_CheckRequiredFields may need edits to best meet this use case.

[JamesBisese]

I found issues when trying to implement the "Download Template" functionality. I can get the system to import a TADA export, but not data that matches the template. The 'TADA.*" fields seem to be required now. I imagine that the requirement got coded in by accident during development of the TADA export/re-import process. I think I know enough to work on this issue now.

[cristinamullin]

Sounds great.

Here is the code from the TADA R Package: https://github.com/USEPA/EPATADA/blob/develop/R/RequiredCols.R.
see lines 342-381 for the EPATADA::TADA_CheckRequiredFields function that can hopefully be leveraged directly for this check.

Some of the TADA columns are required for subsequent TADA functions to run, however a user should still be able to upload a file that includes all the required columns (except the ones with the TADA. prefix). During upload, run EPATADA::TADA_CheckRequiredFields (first - to make sure all required WQP columns are included) and EPATADA::TADA_AutoClean (second - this adds the columns that will be required for the rest of the shiny application tabs to run).

[JamesBisese]

1. Run 'Check Required Fields' and return message to user if any column is not found
2. Run other routines as needed to make data 'complete'
3. Trap errors during routines to report errors to user
   -- this is hard to estimate because trapping errors is not simple and a UI metaphor needs to be implemented for the first time.
   -- 8 - 16 hours

[cristinamullin]

Starting to work on this here: fix-option-C-#135.

See comments and remaining issues related to: #184