* - Added `NativeLogConfig` which allows overriding the llama.cpp log callback
 - Delaying binding of this into llama.cpp until after `NativeLibraryConfig` has loaded

* Using the log callback to show loading log messages during loading.

* Registering log callbacks before any calls to llama.cpp except `llama_empty_call`, this is specifically selected to be a method that does nothing and is just there for triggering DLL loading.

* - Removed much of the complexity of logging from `NativeApi.Load`. It always call whatever log callbacks you have registered.
 - Removed alternative path for `ILogger` in NativeLibraryConfig, instead it redirects to wrapping it in a delegate.

* Saving a GC handle to keep the log callback alive

* Removed prefix, logger should already do that.

* Buffering up messages until a newline is encountered before passing log message to ILogger.

* - Added trailing `\n` to log messages from loading.
 - Using `ThreadLocal<StringBuilder>` to ensure messages from separate threads don't get mixed together.

- Made all the mechanics of grammar parsing (GBNFGrammarParser, ParseState) internal. Just call `Grammar.Parse("whatever")`.
 - Added a `GrammarRule` class which validates elements on construction (this allows constructing grammar without parsing GBNF).
   - It should be impossible for a `GrammarRule` to represent an invalid rule.

- Added some more comments
 - Modified `llama_tokenize` to not allocate
 - Modified `llama_tokenize_native` to take a pointer instead of an array, allowing use with no allocations
 - Removed GgmlInitParams (not used)