Add Cache Storage Size Limit

[nathnaeld]

Feature Request:
Please add a configurable cache storage size limit. This feature would allow to set a maximum cache size, preventing excessive storage usage.

Use Case:
In apps displaying many images, the cache can grow too large, consuming too much storage. A size limit would help manage storage more effectively.

Proposed Implementation:

• Add a parameter for maximum cache size (in bytes) to the configuration:

  await FastCachedImageConfig.init(
    subDir: storageLocation,
    clearCacheAfter: const Duration(days: 7),
    maxCacheSize: 100 * 1024 * 1024, // Example: 100 MB
  );

• Implement logic to remove the least recently used items when the cache exceeds this limit.

[escamoteur]

IMHO it should have two options max-images and max-size. which ever is reached first should trigger deletion of the the oldest entries