ECS: Mount EFS volume

I want to be able to create an EFS volume and mount it in a docker container with CDK.

I tried figuring out how to use an Access Point but can't figure out how to specify the AP ID in a `Volume` definition. Don't see anything about access points in ECS docs.
I tried creating an EFS volume and mounting it but I can't write to it and I have no way to change the permissions. I'm using a community docker image I'd rather use as-is without modifying.

Surely this is a common use case - create a writeable persistent volume and mount it.

### Use Case

I'm building this - https://github.com/jetbridge/lemmy-cdk

### Proposed Solution

A way to mount an EFS access point in a fargate task definition or a way to mount the entire EFS volume as writeable.

### Other

```typescript
const fs = new FileSystem(this, "FS", {
vpc,
encrypted: true,
lifecyclePolicy: LifecyclePolicy.AFTER_60_DAYS,
performanceMode: PerformanceMode.GENERAL_PURPOSE,
removalPolicy: RemovalPolicy.RETAIN,
fileSystemName: "LemmyFS",
enableAutomaticBackups: false,
});

const assetVolume: Volume = {
efsVolumeConfiguration: {
fileSystemId: fs.fileSystemId,
},
name: "assets",
};

const container = taskDef.addContainer(PICTRS_NAME, {
image: ContainerImage.fromRegistry(PICTRS_IMAGE),
logging: LogDriver.awsLogs({ streamPrefix: PICTRS_NAME }),
environment: { PICTRS_PATH: "/mnt/assets" },
});
// mount asset storage volume
container.addMountPoints({
sourceVolume: assetVolume.name,
containerPath: "/mnt/assets",
readOnly: false,
});
```

* [ ] :wave: I may be able to implement this feature request
* [ ] :warning: This feature might incur a breaking change

---

This is a :rocket: Feature Request

Review the ECS task definition's Volume and efsVolumeConfiguration, along with the Fargate task definition and addMountPoints usage shown in the example. Compare the requested EFS access-point or writable-volume behavior with the current CDK model, and define completion as a task definition that mounts persistent EFS storage for the unchanged container image.

Written by the indexing model from the issue text.