Integrate scale package into internal packages

[timwu20]

Task summary

• Evaluate use of custom Encode()/Decode() functionality on struct types. Should all be covered by new Marshal()/Unmarshal() functionality. Remove the Encode()/Decode() receiver functions.
• Change all occurrences of Encode()/Decode() to use new Marshal()/Unmarshal() interface.
• Implement VaryingDataType pattern for existing structs that decode SCALE/Rust enums
• Implement Result pattern for existing use case in lib/runtime/wasmer/imports.go
• Ensure that existing encoded data stored in DB is successfully decoded

Specification reference

• https://github.com/w3f/polkadot-spec/releases/download/v0.1.0-beta1/polkadot-host-spec_v0.1.0-beta1.pdf

Other information and links

• https://github.com/ChainSafe/gossamer/tree/tim/scale/pkg/scale
• https://github.com/paritytech/parity-scale-codec
• https://substrate.dev/docs/en/knowledgebase/advanced/codec

[jimjbrettj]

• lib/babe
• lib/common
• lib/genesis
• lib/grandpa
• lib/runtime
• lib/transaction
• lib/trie
• dot/core
• dot/digest WIP
• dot/network WIP
• dot/rpc
• dot/state
• dot/sync
• dot/types WIP

[noot]

closing as this has been completed