Implemented block format

[dutterbutter]

• Implements block format used prior to block writes

Go Library of Block Format:

• go-block-format

See usage examples in implementations here:

• Lotus- PersistBlock
• Lotus- ToStorageBlock
• Lotus- ToStorageBlockMsg

Closes #147

[austinabell]

You need to add a lib.rs file and also include this crate in the root Cargo.toml if intended to keep this as seperate crate. Why is this not included in the blocks crate by the way? If it is intended to be seperate, the file that the block header is defined in should be changed from block.rs to block_header.rs or something to that effect.

[dutterbutter]

You need to add a lib.rs file and also include this crate in the root Cargo.toml if intended to keep this as seperate crate. Why is this not included in the blocks crate by the way? If it is intended to be seperate, the file that the block header is defined in should be changed from block.rs to block_header.rs or something to that effect.

My main reasoning for keeping it separated from blocks crate it that it mimics the external library used in the lotus implementation and if we wanted to pull it out into its own lib it would be easy. However, I am impartial and can move it into the blocks crate, but will rename it to blk_format rather than renaming blocks.rs which although is mostly blockheader it does define full blocks as well.

[dutterbutter]

Moved RawBlock trait into block.rs for now. Although this will likely be moved into its own crate in the future as it will be used for themessageStore once we get there. However, since that component is incomplete and I am unsure exactly how the message component will use the RawBlock trait accordingly imo makes sense to have it live in block.rs for the time being.