feature request - disabling tokenizer in conversion / inference

in #1764 i asked if it'd be possible to add a Huggingface tokenizer. but - HF tokenizers are quite flexible and officially supporting them in llama.cpp (or ggml?) might be a lot of hassle.

a much easier workaround would be allowing to disable tokenizers in both model conversion and inference. this means the users are supposed to encode(text)/decode(ids) in their implementation for using llama.cpp. in my case, for example, i'll use a python GUI and a wrapper anyway.

i'd like to work on it, but honestly i don't think i understand enough to be able to do this. i'd appreciate very much if anyone's interested in it.