The `ElementId` property in the `Signature` record was renamed to `Id`. This change simplifies the property name, making it more concise and aligning with standard naming conventions or domain terminology.
Replaced the `SignatureDto` record with a new `Signature` record to provide a more robust representation of signature data. Updated `MappingProfile` to map `Signature` to `DocReceiverElement` and removed the old `SignatureDto` mapping. Updated `SigningCommand` to use `IEnumerable<Signature>` instead of `IEnumerable<SignatureDto>`. Removed the old `MappingProfile` class and adjusted namespaces and `using` directives accordingly. These changes improve maintainability and streamline signature handling.
