Limit tribute autocomplete menu items to 100

What does this MR do?

We are in the process of migrating from atjs (deprecated and jQuery-based) to tribute for autocomplete under the feature flag tribute_autocomplete (defaulted to off).

When testing tribute autocomplete on gitlab.com, issue autocomplete renders tens of thousands of items in the autocomplete menu which freezes the UI for a couple of seconds. This is because tribute by default renders all list items. To improve performance, this MR adds a limit of 100 items, which is still more than the limit of 5 we currently have with atjs autocomplete.

Related epic: &4002

Screenshots (strongly suggested)

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

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• 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