Add string comparison asserts for writer tests with various floats/doubles with accurate expected strings. Comparing to the strings from Newtonsoft.Json won't work for all cases, and we should split up those special cases into their own tests with hard-coded strings.

Writing trailing zeros for float/double/decimal number differ. For example:

• "0" vs "0.0"
• "message": -1588732675085190 vs. "message": -1588732675085190.0