Migrate ee/spec/javascripts/approvals/ to Jest

Description

Let's migrate the specs in ee/spec/javascripts/approvals/ from Karma to Jest.

See the related epic for how to do this.

• ee/spec/javascripts/approvals/stores/modules/project_settings/actions_spec.js
• ee/spec/javascripts/approvals/components/hidden_groups_item_spec.js !31443 (merged)
• ee/spec/javascripts/approvals/components/app_spec.js
• ee/spec/javascripts/approvals/components/modal_rule_create_spec.js !31443 (merged)
• ee/spec/javascripts/approvals/components/mr_edit/mr_rules_hidden_inputs_spec.js !31443 (merged)
• ee/spec/javascripts/approvals/components/mr_edit/app_spec.js
• ee/spec/javascripts/approvals/components/mr_edit/mr_rules_spec.js
• ee/spec/javascripts/approvals/components/approvers_select_spec.js
• ee/spec/javascripts/approvals/components/rule_controls_spec.js !31443 (merged)
• ee/spec/javascripts/approvals/components/rule_form_spec.js !31443 (merged)
• ee/spec/javascripts/approvals/components/project_settings/project_rules_spec.js !31443 (merged)
• ee/spec/javascripts/approvals/mocks.js !31443 (merged)