Add localStorage support for sort issue and MR notes

What does this MR do?

This is a fast follow of !26929 (merged). This MR addresses part of the criteria required: #14588 (closed)

Allows for a user to persist settings of Newest first vs Oldest first with regards to the Issue or MR notes sort order.

How to repro?

• rails console
• Feature.enable(:sort_discussions)
• Go to an Issue or an MR and change the sort direction, then do to another issue or MR and notice the sort order is consistent. (Note: Issues and MR discussions sort order are managed individually, ie if you make a change to an Issue sort order you will not see the change in the MR sort order.)

Screenshots

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