feat(storage): generic cache interface (#8628)

# Which Problems Are Solved

We identified the need of caching.
Currently we have a number of places where we use different ways of
caching, like go maps or LRU.
We might also want shared chaches in the future, like Redis-based or in
special SQL tables.

# How the Problems Are Solved

Define a generic Cache interface which allows different implementations.

- A noop implementation is provided and enabled as.
- An implementation using go maps is provided
  - disabled in defaults.yaml
  - enabled in integration tests
- Authz middleware instance objects are cached using the interface.

# Additional Changes

- Enabled integration test command raceflag
- Fix a race condition in the limits integration test client
- Fix a number of flaky integration tests. (Because zitadel is super
fast now!) 🎸 🚀

# Additional Context

Related to https://github.com/zitadel/zitadel/issues/8648

internal/integration/config/zitadel.yaml

@@ -6,6 +6,23 @@ ExternalSecure: false
 TLS:
   Enabled: false
 
+Caches:
+  Connectors:
+    Memory:
+      Enabled: true
+      AutoPrune:
+        Interval: 30s
+        TimeOut: 1s
+  Instance:
+    Connector: "memory"
+    MaxAge: 1m
+    LastUsage: 30s
+    Log:
+      Level: info
+      AddSource: true
+      Formatter:
+        Format: text
+
 Quotas:
   Access:
     Enabled: true