add bound-arguments and instance to span handlers (#12378)

...index-core/llama_index/core/instrumentation/dispatcher.py

...re/llama_index/core/instrumentation/span_handlers/base.py

...re/llama_index/core/instrumentation/span_handlers/null.py

.../llama_index/core/instrumentation/span_handlers/simple.py

llama-index-core/llama_index/core/llms/llm.py

llama-index-core/pyproject.toml

llama-index-core/tests/instrumentation/test_dispatcher.py