Fixes issues #493, #494, #495: Refactor NCA integration functions

[PavanLomati]

• Remove aumc_integrate function #493: Removed aumc_integrate() function and simplified its use by calling auc_integrate() with appropriate fun_linear, fun_log, and fun_inf arguments.
• Rename pk.calc.aucint() to pk.calc.auxcint() and generalize its use for AUC or AUMC #494: Refactored pk.calc.aucint() and pk.calc.aumcint():
  • Renamed pk.calc.aucint() to pk.calc.auxcint() with integration functions passed as arguments.
  • Created new, simpler pk.calc.aucint() and pk.calc.aumcint() that call pk.calc.auxcint() with correct integration functions.
• Rename pk.calc.auciv() to pk.calc.auxciv() and generalize its use #495: Applied same refactoring to pk.calc.auciv() and pk.calc.aumciv() functions.
• Updated NEWS.md with these changes.

[billdenney]

Thank you for this update. Please also add this and the prior changes to NEWS.md and rebuild the documentation with devtools::document().

[billdenney]

Please re-add the ... argument. It helps absorb some extraneous arguments which occasionally come through.

[PavanLomati]

Added ... argument to pk.calc.auxcint and pk.calc.auxc

[PavanLomati]

Added ... argument to pk.calc.auxcint and pk.calc.auxc. Updated #' @describeIn for pk.calc.auxciv and pk.calc.auxcint. Updated NEWS.Rmd.
Updating PKNCA documentation
ℹ Loading PKNCA
✖ In topic 'pk.calc.aucint.Rd': Skipping; no name and/or title.
✖ In topic 'pk.calc.aumcint.Rd': Skipping; no name and/or title.
✖ In topic 'pk.calc.auciv.Rd': Skipping; no name and/or title.

[billdenney]

The testing indicates only 67% of the patch has tests associated with it. Please add tests so that the patch has 100% coverage.

You can see the missed lines for code coverage by

1. clicking on the "codecov/patch" link above
2. Clicking "view this pull request on codecov"
3. Click on the "file explorer" tab
4. Navigate through the R directory and files to find places where you added code that do not have a test
5. Add the test in the "tests/testthat/test-[filename].R" where "[filename]" is the same as the filename with the R code. (If you have the file open in your R session, you can use usethis::use_test() and choose not to overwrite the test file, and it will open for you in Rstudio.)