feat: actions v2 for functions (#9420)

# Which Problems Are Solved

Actions v2 are not executed in different functions, as provided by the
actions v1.

# How the Problems Are Solved

Add functionality to call actions v2 through OIDC and SAML logic to
complement tokens and SAMLResponses.

# Additional Changes

- Corrected testing for retrieved intent information
- Added testing for IDP types
- Corrected handling of context for issuer in SAML logic

# Additional Context

- Closes #7247 
- Dependent on https://github.com/zitadel/saml/pull/97
- docs for migration are done in separate issue:
https://github.com/zitadel/zitadel/issues/9456

---------

Co-authored-by: Silvan <27845747+adlerhurst@users.noreply.github.com>

internal/domain/flow.go

@@ -1,7 +1,6 @@
 package domain
 
 import (
-	"slices"
 	"strconv"
 )
 
@@ -150,20 +149,3 @@ func (s TriggerType) LocalizationKey() string {
 		return "Action.TriggerType.Unspecified"
 	}
 }
-
-func AllFunctions() []string {
-	functions := make([]string, 0)
-	for _, flowType := range AllFlowTypes() {
-		for _, triggerType := range flowType.TriggerTypes() {
-			functions = append(functions, flowType.LocalizationKey()+"."+triggerType.LocalizationKey())
-		}
-	}
-	return functions
-}
-
-func FunctionExists() func(string) bool {
-	functions := AllFunctions()
-	return func(s string) bool {
-		return slices.Contains(functions, s)
-	}
-}