23.02.2: Feat/70 use ext import module

[arunge]

ReSources 23.02.2

New Features

• the Import Data module is now imported from the package DataTools (#70, PR #72)
• additionally to file import, now import from URL or from Pandora Platform is possible
• specific checks for matrix imports are integrated into the new Import Data module
• all redundant code was removed
• using "file" as default source in Import Data (to keep the familiar behavior)

[arunge]

@f-lukas It was quite challenging to make the module run within Resources since

• Resources expects a matrix output
  • for covariates specific checks must be fulfilled, e.g. regarding column and row names, and
• Resources has an additional option for batch imports.

I needed several new tests (in the testthat folder) to make this work, see e.g. https://github.com/Pandora-IsoMemo/data-tools/pull/16

Can you test the Import Data buttons with some random imports? You can use "Pandora Platform" as Source. Question is, do the checks prevent the app to crash? If checks disable not allowed data, all is fine.