Type conversion is now done in the property rather than the utils class and uses the System.Convert class to ensure consistency.

* Added a bool to sbyte Utils convertor

As an attempt to avoid using any MarshalAs attribute for .Net Framework support this Utils method will take in a bool value and return a 1 for true or 0 for false sbyte.

* Changed all bool "MarshalAs" types to sbytes

Changed all previous BOOL types with "MarshalAs" attributes to SBYTEs and changed all the setters of them to use the Utils.BoolToSignedByte() convertor method.

* Fixed Utils bool convertor & added sbyte to bool

Improved the Utils bool convertor just casting an sbyte value to get rid of the unneeded sbyte array and added an sbyte to bool convertor to convert back the way to a C# bool assuming any positive value above 0 is a bool and no bools are packed in the single byte integer.

* bool to & from sbyte conversions via properties

All 1byte bools are now handled where they "sit", via public properties which perform the conversions to keep all external data able to communicate as it did before.

- Moved repeated code to convert `LLamaTokenDataArray` into a `LLamaTokenDataArrayNative` into a helper method.
   - Modified all call sites to dispose the `MemoryHandle`
 - Saved one copy of the `List<LLamaTokenData>` into a `LLamaTokenData[]` in `LlamaModel`