new benchmarks + small updates

[ngc92]

a few small updates:

• error message in case of GPU oversubscription
• better logging messages
• new command line options for seed + better cli validation
• copying config files (e.g., tokenizer.json) to exported model

update benchmarks in readme. add additional files under /benchmarks that contain the actual commands used for easier replication. also, add baseline configs for llama-factory on the 4090.