Decouple scda from teal

[donyunardi]

Related to insightsengineering/nestdevs-tasks#1

Summary

After careful observation, it appears that the scda package is not essential for teal. Consequently, it is advantageous for us to separate scda from teal.

Files affected:

• dummy_functions.R
• init.R (examples)
• modules_debugging.R (examples)
• validations.R (examples)
• including-adam-data-in-teal.Rmd
• preprocessing-data.Rmd

Acceptance Criteria

• Use iris, mtcars, or create a minimal example data that resides only within the package for unit tests and roxygen examples.
  This minimal example data will be stored as .rda files in the /data folder.
• Revise the roxygen examples to use the minimal example data.
• If applicable, Update the unit tests to utilize the new data.
• Update affected vignettes.
• Update DESCRIPTION file to remove scda and related packages.
• Update staged_dependencies.yml