Refactor understrap_entry_footer()

[IanDelMar]

Description

This PR refactors understrap_entry_footer() in order to

• reduce complexity
• increase readability
• make it easier for child themes to not display components of the entry footer by e.g. defining function understrap_tags_list() { return; }

Motivation and Context

See above.

Types of changes

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

None of these.

Checklist:

• I pulled my branch from develop.
• I am submitting my pull request to develop.
• I have resolved any conflicts merging this pull request would create.
• I have checked that there aren't other open Pull Requests for the same update/change.
• My code follows the code style of this project.
• I have performed a self-review of my own code.
• I have commented my code, particularly in hard-to-understand areas.
• (Optional) My change requires a change to the documentation.
• (Optional) I have updated the documentation accordingly.
• (Optional) My change requires a change to the translations.
• (Optional) I have updated the translations accordingly.
• composer cs:check has passed locally.
• composer lint:php has passed locally.
• I have read the CONTRIBUTING document.

Related Issues or Roadmap requests

Further comments

PHPStan errors addressed in #1830

[IanDelMar]

@bacoords ready for review