feat(saml): allow setting nameid-format and alternative mapping for transient format (#7979)

# Which Problems Are Solved

ZITADEL currently always uses
`urn:oasis:names:tc:SAML:2.0:nameid-format:persistent` in SAML requests,
relying on the IdP to respect that flag and always return a peristent
nameid in order to be able to map the external user with an existing
user (idp link) in ZITADEL.
In case the IdP however returns a
`urn:oasis:names:tc:SAML:2.0:nameid-format:transient` (transient)
nameid, the attribute will differ between each request and it will not
be possible to match existing users.

# How the Problems Are Solved

This PR adds the following two options on SAML IdP:
- **nameIDFormat**: allows to set the nameid-format used in the SAML
Request
- **transientMappingAttributeName**: allows to set an attribute name,
which will be used instead of the nameid itself in case the returned
nameid-format is transient

# Additional Changes

To reduce impact on current installations, the `idp_templates6_saml`
table is altered with the two added columns by a setup job. New
installations will automatically get the table with the two columns
directly.
All idp unit tests are updated to use `expectEventstore` instead of the
deprecated `eventstoreExpect`.

# Additional Context

Closes #7483
Closes #7743

---------

Co-authored-by: peintnermax <max@caos.ch>
Co-authored-by: Stefan Benz <46600784+stebenz@users.noreply.github.com>

internal/command/idp_intent_test.go

@@ -6,6 +6,7 @@ import (
 	"testing"
 
 	"github.com/crewjam/saml"
+	"github.com/muhlemmer/gu"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	"github.com/zitadel/oidc/v3/pkg/oidc"
@@ -631,6 +632,8 @@ func TestCommands_AuthFromProvider_SAML(t *testing.T) {
 								[]byte("certificate"),
 								"",
 								false,
+								gu.Ptr(domain.SAMLNameIDFormatUnspecified),
+								"",
 								rep_idp.Options{},
 							)),
 					),
@@ -649,6 +652,8 @@ func TestCommands_AuthFromProvider_SAML(t *testing.T) {
 								}, []byte("-----BEGIN CERTIFICATE-----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\nOxVyt5XkHq1tWwVyBmFp\n-----END CERTIFICATE-----\n"),
 								"",
 								false,
+								gu.Ptr(domain.SAMLNameIDFormatUnspecified),
+								"",
 								rep_idp.Options{},
 							)),
 					),