lib/utilities: refactor _bash-it-pluralize-component() & other improvements

[gaelicWizard]

Please review commit notes as appropriate.

Description

• Refactor function _bash-it-pluralize-component();
• Remove dependencies from _bash-it-component-item-is-enabled() (so it's much faster);
• Fix _bash-it-component-help() for long component names;
• Clean up tests a little.

Motivation and Context

Refactoring _bash-it-pluralize-component() started by accident while fiddling with bash-it search and resulted in:

• renaming the function so it better matches it's siblings,
• adding a matching _bash-it-component-singularize() which can be used when logging and other places,
• using printf's -v flag to store to a variable, rather than echoing to stdout to reduce subshells,
• updating _bash-it-component-cache-file() and _bash-it-component-help() to use the variable,
• updating _bash-it-component-cache-file() to use printf -v too.

Alsö, misc fixes to lib/utilities that came along with the branch and deobfuscation of tests/utilities.

How Has This Been Tested?

These fixes have long been part of my main branch and my shellcheck branch(es), and all automated tests pass.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• If my change requires a change to the documentation, I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• If I have added a new file, I also added it to clean_files.txt and formatted it using lint_clean_files.sh.
• I have added tests to cover my changes, and all the new and existing tests pass.

[gaelicWizard]

@tsiflimagas, want to take a look at this one too? 😆

[NoahGorny]

we can merge this after #2002

[gaelicWizard]

we can merge this after #2002

@NoahGorny, I don't think any of this depends on my BATS branch