Allow access to verbose struct entries & F128 values

What's Changed

• Add entries and entries_raw_data methods to verbose::StructValue to allow access to fields
• Corrected serde::Serialize implementation for verbose::StructValue to serialize the field values
• Add RawF128 with methods to access byte representations.
• Further RawF16 implementations
• Add example for manual printing of verbose data

Full Changelog: v0.8.4...v0.9.0