Fix users finder in MRs & Commits list - support query blocked users

Issue: #368339 (closed)

What does this MR do and why and how?

Fix these two bugs:

1. Search for blocked user in MR list page, it cannot be searched
2. Search for blocked user in Commits list page, it cannot be searched

What has changed in the sql query?

Raw SQL

SELECT
  "users".*
FROM
  "users"
  INNER JOIN "project_authorizations" ON "users"."id" = "project_authorizations"."user_id"
WHERE
  "project_authorizations"."project_id" = 6
  AND "users"."state" IN ('active', 'blocked')
  AND (
    "users"."user_type" IS NULL
    OR "users"."user_type" IN (6, 4)
  )
ORDER BY
  "users"."name" ASC
LIMIT
  20

(This SQL is triggered at Autocomplete::UsersFinder#limited_users)

Screenshots

Before	After
MRs page: only return active users	MRs page: return active and blocked users
Commmts page: only return active users	Commmts page: return active and blocked users

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cc @prajnamas @icbd @zhzhang93 @JeremyWuuuuu @qk44077907