[FEATURE] Possibility to get the Base64 representation of a BLOB from the API

[BlackRose01]

Is your feature request related to a problem? Please describe.
I have some AAS files in JSON format. Each AAS contains a BLOB dataelement for the ProductImage (similar to Submodel TechnicalData). When I use the BaSyx AAS SM Repository to get the value of the BLOB dataelement via REST I receive the raw binary value in JSON. Here is it currently (for me) not possible to store the file in the required format.

Describe the solution you'd like
I would like to have an option to choose if I would like receive the Base64 representation of the BLOB dataelement in base64 (stored in file) or as decoded presentation (currently response).

Alternative Idea
An additional endpoint to request BLOB dataelements in Base64 or as decoded value.

Example:
/submodels/{submodelIdentifier}/submodel-elements/{idShortPath}/$value?blob_in_base64=true

Example File
full_AAS_Trims_S07EA.json

[BlackRose01]

After some while with testing it is not possible for me to get the image uncorrupted from ProductImage. I also tried with Copilot, Chat-GPT and Claude. But all mentioned that the property contains incorrectly encoded binary data—in particular, the character � (\ufffd), which is a placeholder for invalid bytes. This character cannot be converted back to true binary format because it is already a lossy representation.