Join identities in MembershipProfiles.LoadExistingByIDs

SCIM event CSV exports failed with "cannot parse address :
mail: no address" because this query selected a placeholder
empty string for email_address instead of the real address, and
scanning it into mail.Addr tried to parse it as one.

Join identities the same way every other MembershipProfile query
already does, and drop the redundant identity lookup in the SCIM
export path now that profiles carry their real email address.

Signed-off-by: Bryan Frimin <bryan@probo.com>

pkg/coredata/membership_profile.go

@@ -506,7 +506,7 @@ SELECT
     p.id,
     p.identity_id,
     p.organization_id,
-    ''::citext AS email_address,
+    i.email_address,
     p.source,
     p.state,
     p.full_name,
@@ -541,6 +541,8 @@ SELECT
     p.updated_at
 FROM
     iam_membership_profiles p
+INNER JOIN identities i
+    ON i.id = p.identity_id
 WHERE
     p.%s
     AND p.id = ANY(@profile_ids)