Add endpoint to access account storage

#### Description
The current implementation of the wallet adapter does not provide access to private account storage. To enhance the functionality of the adapter, we need to introduce a new method that allows access to this storage.

#### Proposed Solution
Create a new method in the wallet adapter that enables access to private account storage. This method should be designed with security and privacy in mind, ensuring that sensitive information is handled appropriately.
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#### Requirements
- The new method should be able to retrieve and store data securely.
- It should be well-documented, including clear instructions on usage and any security considerations.
- The method should be tested thoroughly to ensure it works as expected and does not introduce any security vulnerabilities.
- The new method should integrate with existing permissions and perhaps should adapt permissions to limit access to account storage.