Draft: Resolve "Standardize clickable titles in settings"

What does this MR do?

In the Project Settings, the sections of each page can be expanded/collapsed by the Expand/Collapse button on the right of the section title.

In the Project Settings "Default" page, the section titles support expand/collapse on the section title texts (h4 elements "onclick/ontap" behaviour), in addition to the Expand/Collapse buttons.

This MR adds the onclick/ontap expand/collapse behaviour to (most) other Project Settings section titles (h4 elements). This is related to #205484.

Screenshots (strongly suggested)

• 1.A - Project Settings / General / collapsed - mouse onclick or button

• 1.B - Project Settings / General / expanded - mouse onclick or button

• 2.A - Project Settings / Repository / collapsed - button only

• 2.B - Project Settings / Repository / expanded - button only

• 3.A - Project Settings / Repository / collapsed - mouse onclick or button - with <h4 class="settings-title js-settings-toggle js-settings-toggle-trigger-only">

• 3.B - Project Settings / Repository / expanded - mouse onclick or button - with <h4 class="settings-title js-settings-toggle js-settings-toggle-trigger-only">

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required) -- May not be required. I do not find the expand/collapse behavior mentioned in the documentation.
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides -- May not be required. No database changes.
• Separation of EE specific content

Availability and Testing

This MR adds CSS classes settings-title, js-settings-toggle and js-settings-toggle-trigger-only to h4 elements on Project Settings pages.

For changes to Haml view templates, I see little risk of tests failing, unless there are frontend snapshot test. I need to investigate this. For changes to Vue.js templates/components, I updated related frontend snapshot tests.

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
  • Apple Safari 13.1.2 (13609.3.5.1.5)
  • Chromium Version 90.0.4409.0
  • Google Chrome 88.0.4324.146
  • Microsoft Edge 88.0.705.56
  • Mozilla Firefox 84.0.2
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

This MR only updates Haml/Vue.js view templates/compontents (and may be frontend snapshot tests).

I do not yet see any security affecting changes.

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team

Related to #205484