Feature: align with lmstudio.js 1.0.0 config support

[ncoghlan]

While the Python SDK will accept speculative decoding config settings, it won't actually send them to the server (see #32).

This issue covers adding those key to the interim config key mapping in _kv_config.py

It also covers adding support for the other config keys that lmstudio-python 1.0.1 accepts but doesn't forward to the server:

• disabledGpus (in the gpuOffload settings)
• reasoningParsing

In addition to supporting the above missing keys, this feature also covers implementing the reverse mapping from server configuration settings to SDK client configuration settings, and making the config retrieval/reporting methods and fields public after updating them to return the client settings format rather than the server format.