chore: add cache configurations objects (#32)

lib/src/config/cache_configuration.dart

@@ -0,0 +1,36 @@
+import 'package:client_sdk_dart/src/config/transport/grpc_configuration.dart';
+import 'package:client_sdk_dart/src/config/transport/transport_strategy.dart';
+
+abstract interface class CacheConfiguration {
+  /// Configures low-level options for network interactions with the Momento service
+  late TransportStrategy transportStrategy;
+
+  /// Constructor for a CacheConfiguration
+  CacheConfiguration(this.transportStrategy);
+
+  /// Copy constructor for overriding TransportStrategy
+  CacheConfiguration withTransportStrategy(TransportStrategy transportStrategy);
+
+  /// Convenience copy constructor that updates the client-side
+  /// timeout setting in the transport strategy
+  CacheConfiguration withDeadline(Duration deadline);
+}
+
+class CacheClientConfiguration implements CacheConfiguration {
+  @override
+  late TransportStrategy transportStrategy;
+
+  CacheClientConfiguration(this.transportStrategy);
+
+  @override
+  CacheConfiguration withTransportStrategy(
+      TransportStrategy transportStrategy) {
+    return CacheClientConfiguration(transportStrategy);
+  }
+
+  @override
+  CacheConfiguration withDeadline(Duration deadline) {
+    return CacheClientConfiguration(
+        StaticTransportStrategy(StaticGrpcConfiguration(deadline)));
+  }
+}

lib/src/config/cache_configurations.dart

@@ -0,0 +1,19 @@
+import 'package:client_sdk_dart/src/config/transport/grpc_configuration.dart';
+import 'package:client_sdk_dart/src/config/transport/transport_strategy.dart';
+
+import 'cache_configuration.dart';
+
+/// Prebuilt configurations for Momento Cache clients
+abstract interface class CacheClientConfigurations {}
+
+/// Provides prebuilt configurations for the `CacheClient` on mobile platforms
+class Mobile extends CacheClientConfigurations {
+  static CacheClientConfiguration defaultConfig() {
+    return latest();
+  }
+
+  static CacheClientConfiguration latest() {
+    return CacheClientConfiguration(StaticTransportStrategy(
+        StaticGrpcConfiguration(Duration(seconds: 15))));
+  }
+}