Move keyboard shortcut help modal to Vue

What does this MR do?

Currently the keyboard shortcut modal is rendered via HAML and injected into the DOM via JavaScript eval. This is rather inefficient and might even introduce security vulnerabilities. Thus we move the static HAML file to be a conditionally rendered Vue Component instead.

Screenshots

Here is a screencast showing that ? (Shift + / on my keyboard) and the help drop down work in opening the help. Also shown in the video, closing with: Retriggering ?, Esc, Click outside the modal, Click on the X in the modal header and clicking outside the Modal.

keyboard-shortcuts

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

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