get_raw_block api endpoint

[huangminghuang]

This PR

• adds the following API endpoints
  • /v1/chain/get_raw_block: returns the raw block content without ABI decoding
  • /v1/chain/get_block_header: returns the block header with optional block extensions
    • Input/output:

  struct get_raw_block_header_params {
     string block_num_or_id;
     bool include_extensions = false; // include block extensions (requires reading entire block off disk)
  }; 
  
  struct get_raw_block_header_results {
     chain::block_id_type  id;
     fc::variant           signed_block_header;
     std::optional<chain::extensions_type> block_extensions;
  };
  

• add cleos get block options for the added API endpoints above
  • --raw: corresponding to get_raw_block
  • --header: corresponding to get_block_header with include_extensions set to false
  • --header_with_extensions: corresponding to get_block_header with include_extensions set to true

Resolves #642

[linh2931]

You have an extra equal to 64 checked while greater than 0 is not checked. This is not blocking. You can fix in RC.

[huangminghuang]

I believe the assertion condition is right but the message description was problematic, fixed in commit af1dcf2

[linh2931]

No try block for db.fetch_block_header_by_number?

[huangminghuang]

The try you saw in the else was thrown from the type conversion from string to block_id_type, not from the fetch_block_header_by_id itself. In this line, the block_num is already the right type; therefore, its not going to throw here. This is exactly the same logic with get_raw_block() in line 1920.