feat(v3alpha): write actions (#8225)

# Which Problems Are Solved

The current v3alpha actions APIs don't exactly adhere to the [new
resources API
design](https://zitadel.com/docs/apis/v3#standard-resources).

# How the Problems Are Solved

- **Breaking**: The current v3alpha actions APIs are removed. This is
breaking.
- **Resource Namespace**: New v3alpha actions APIs for targets and
executions are added under the namespace /resources.
- **Feature Flag**: New v3alpha actions APIs still have to be activated
using the actions feature flag
- **Reduced Executions Overhead**: Executions are managed similar to
settings according to the new API design: an empty list of targets
basically makes an execution a Noop. So a single method, SetExecution is
enough to cover all use cases. Noop executions are not returned in
future search requests.
- **Compatibility**: The executions created with previous v3alpha APIs
are still available to be managed with the new executions API.

# Additional Changes

- Removed integration tests which test executions but rely on readable
targets. They are added again with #8169

# Additional Context

Closes #8168

internal/command/action_v2_execution_model.go

@@ -16,6 +16,18 @@ type ExecutionWriteModel struct {
 	ExecutionTargets []*execution.Target
 }
 
+func (e *ExecutionWriteModel) ExecutionTargetsEqual(targets []*execution.Target) bool {
+	if len(e.ExecutionTargets) != len(targets) {
+		return false
+	}
+	for i := range e.ExecutionTargets {
+		if e.ExecutionTargets[i].Type != targets[i].Type || e.ExecutionTargets[i].Target != targets[i].Target {
+			return false
+		}
+	}
+	return true
+}
+
 func (e *ExecutionWriteModel) IncludeList() []string {
 	includes := make([]string, 0)
 	for i := range e.ExecutionTargets {