Fix: Choose Lookup params per auth module (#397)

Co-authored-by: Karl Persson <kalle.persson@grafana.com>

Fix: Prefer pointer to struct in lookup

Co-authored-by: Karl Persson <kalle.persson@grafana.com>

Fix: user email for ldap

Co-authored-by: Karl Persson <kalle.persson@grafana.com>

Fix: Use only login for lookup in LDAP

Co-authored-by: Karl Persson <kalle.persson@grafana.com>

Fix: use user email for ldap

Co-authored-by: Karl Persson <kalle.persson@grafana.com>

fix remaining test

fix nit picks

pkg/api/ldap_debug.go

@@ -219,6 +219,11 @@ func (hs *HTTPServer) PostSyncUserWithLDAP(c *models.ReqContext) response.Respon
 		ReqContext:    c,
 		ExternalUser:  user,
 		SignupAllowed: hs.Cfg.LDAPAllowSignup,
+		UserLookupParams: models.UserLookupParams{
+			UserID: &query.Result.Id, // Upsert by ID only
+			Email:  nil,
+			Login:  nil,
+		},
 	}
 
 	err = hs.Login.UpsertUser(c.Req.Context(), upsertCmd)