Jira Connect: show all namespaces when search term length < 3

What does this MR do?

The fetchGroups endpoint only returns results when the search term is 0, or >= 3 in length.

This MR changes the frontend logic to ensure all results are returned when search term is < 3. This is the desired UX for now (see discussions #327658 (comment 551131292), and !61099 (comment 571057610))

Screenshots (strongly suggested)

better-jira-search

Does this MR meet the acceptance criteria?

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Related to #327658 (closed)