adding ard_fishertest()

[ddsjoberg]

What changes are proposed in this pull request?
Migrated ard_fishertest() from {cards}

---

Reviewer Checklist (if item does not apply, mark is as complete)

• Ensure all package dependencies are installed: devtools::install_dev_deps()
• PR branch has pulled the most recent updates from master branch: usethis::pr_merge_main()
• If a bug was fixed, a unit test was added.
• Run pkgdown::build_site(). Check the R console for errors, and review the rendered website.
• Code coverage is suitable for any new functions/features: devtools::test_coverage()
• usethis::use_spell_check() runs with no spelling errors in documentation

When the branch is ready to be merged:

• Update NEWS.md with the changes from this pull request under the heading "# cards (development version)". If there is an issue associated with the pull request, reference it in parentheses at the end update (see NEWS.md for examples).
• Increment the version number using usethis::use_version(which = "dev")
• Run usethis::use_spell_check() again
• Approve Pull Request
• Merge the PR. Please use "Squash and merge".

[github-actions]

Unit Tests Summary

 1 files   7 suites   1s ⏱️
 7 tests  6 ✅ 1 💤 0 ❌
17 runs  14 ✅ 3 💤 0 ❌

Results for commit e70755d.

♻️ This comment has been updated with latest results.

[github-actions]

Unit Test Performance Difference

Test Suite	$Status$	Time on main	$±Time$	$±Tests$	$±Skipped$	$±Failures$	$±Errors$
ard_fishertest	👶		$+0.81$	$+2$	$0$	$0$	$0$

Additional test case details

Test Suite	$Status$	Time on main	$±Time$	Test Case
ard_fishertest	👶		$+0.81$	ard_fishertest_works

Results for commit c15053f

♻️ This comment has been updated with latest results.

[github-actions]

Code Coverage Summary

Filename              Stmts    Miss  Cover    Missing
------------------  -------  ------  -------  ---------
R/ard_chisqtest.R        31       0  100.00%
R/ard_fishertest.R       33       0  100.00%
R/ard_ttest.R            78       0  100.00%
R/ard_wilcoxtest.R       83       0  100.00%
TOTAL                   225       0  100.00%

Diff against main

Filename              Stmts    Miss  Cover
------------------  -------  ------  --------
R/ard_fishertest.R      +33       0  +100.00%
TOTAL                   +33       0  +100.00%

Results for commit: e70755d

Minimum allowed coverage is 80%

♻️ This comment has been updated with latest results

[zdz2101]

LGTM

[ddsjoberg]

Thank you @zdz2101 !!