perf(query): reduce user query duration (#10037)

# Which Problems Are Solved

The resource usage to query user(s) on the database was high and
therefore could have performance impact.

# How the Problems Are Solved

Database queries involving the users and loginnames table were improved
and an index was added for user by email query.

# Additional Changes

- spellchecks
- updated apis on load tests

# additional info

needs cherry pick to v3

cmd/setup/58/01_update_login_names3_view.sql

@@ -0,0 +1,36 @@
+CREATE OR REPLACE VIEW projections.login_names3 AS
+    SELECT
+        u.id AS user_id
+        , CASE
+            WHEN p.must_be_domain THEN CONCAT(u.user_name, '@', d.name)
+            ELSE u.user_name
+        END AS login_name
+        , COALESCE(d.is_primary, TRUE) AS is_primary
+        , u.instance_id
+    FROM
+        projections.login_names3_users AS u
+    LEFT JOIN LATERAL (
+        SELECT
+            must_be_domain
+            , is_default
+        FROM
+            projections.login_names3_policies AS p
+        WHERE
+            (
+                p.instance_id = u.instance_id
+                AND NOT p.is_default
+                AND p.resource_owner = u.resource_owner
+            ) OR (
+                p.instance_id = u.instance_id
+                AND p.is_default
+            )
+        ORDER BY
+            p.is_default -- custom first
+        LIMIT 1
+    ) AS p ON TRUE
+    LEFT JOIN 
+        projections.login_names3_domains d
+        ON 
+            p.must_be_domain 
+            AND u.resource_owner = d.resource_owner 
+            AND u.instance_id = d.instance_id

cmd/setup/58/02_create_index.sql

@@ -0,0 +1 @@
+CREATE INDEX CONCURRENTLY IF NOT EXISTS login_names3_policies_is_default_owner_idx ON projections.login_names3_policies (instance_id, is_default, resource_owner) INCLUDE (must_be_domain)