Resolve "Issue picker buttons don’t overflow nicely"

What does this MR do?

The picker buttons are wrapping in a strange and disproportionate way. This MR is to make it so that the emoji/likes buttons sit comfortably side by side with the 3 dropdowns in larger views and wrap as sections in smaller.

I removed the 6 and 12 column classes as it was forcing unnecessary spacing between these divs and then applied some margin to ensure that the spacing is consistent and in alignment with the other elements in this column.

Screenshots

Before	After

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

Closes #215965 (closed)