Migrate spec/javascripts/issue_show/ to Jest

The following test files should be refactored from Karma to Jest:

find spec/javascripts/issue_show -name '*_spec.js' -exec echo "- [ ] {}" \;

• spec/javascripts/issue_show/index_spec.js
• spec/javascripts/issue_show/components/form_spec.js
• spec/javascripts/issue_show/components/edit_actions_spec.js
• spec/javascripts/issue_show/components/description_spec.js
• spec/javascripts/issue_show/components/edited_spec.js
• spec/javascripts/issue_show/components/app_spec.js
• spec/javascripts/issue_show/components/title_spec.js
• spec/javascripts/issue_show/components/fields/description_spec.js
• spec/javascripts/issue_show/components/fields/description_template_spec.js
• spec/javascripts/issue_show/components/fields/title_spec.js