Issue 555: Rename interval_coverage_ family and remove sample version

[seabbs]

Description

This PR closes #555.

It removes interval_coverage_sample() and renames interval_coverage_quantile() and interval_coverage_dev_quantile() to interval_coverage() and interval_coverage_deviation().

Note that I have stored some of the useful helper code from interval_coverage_sample() in #557

By removing interval_coverage_sample() this PR also closes #411.

Checklist

• My PR is based on a package issue and I have explicitly linked it.
• I have included the target issue or issues in the PR title as follows: issue-number: PR title
• I have tested my changes locally.
• I have added or updated unit tests where necessary.
• I have updated the documentation if required.
• I have built the package locally and run rebuilt docs using roxygen2.
• My code follows the established coding standards and I have run lintr::lint_package() to check for style issues introduced by my changes.
• I have added a news item linked to this PR.
• I have reviewed CI checks for this PR and addressed them as far as I am able.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (10641d6) 84.55% compared to head (62b5dd3) 85.14%.
Report is 7 commits behind head on develop.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop     #558      +/-   ##
===========================================
+ Coverage    84.55%   85.14%   +0.59%     
===========================================
  Files           21       21              
  Lines         1722     1710      -12     
===========================================
  Hits          1456     1456              
+ Misses         266      254      -12     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[nikosbosse]

Looks good to me. Thank you!