SC new Chain functions

[Neylix]

Description

Add new functions in Chain module:

• get_previous_address => return the previous address from previous public key or a transaction
• get_balance => return a map containing the balance of uco and tokens
• get_uco_balance => return the amount of uco
• get_token_balance => return the amount of token
• get_tokens_balance => return a map of token as for the get_balance but only with selected tokens

balance returns a map as

[
  uco: 1234,
  tokens: [
    [token_address: "1234", token_id: 0]: 1234,
    [token_address: "123456", token_id: 1]: 1,
  ]
]

It can be used like this

    balance = Chain.get_balance(previous_address)
    token = [
      token_address: 0x000123...,
      token_id: 0
    ]

    token_balance = Map.get(balance.tokens, token, 0)
    token_balance >= amount

Type of change

• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

Unit test and tested with real bridge smart contract

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

[bchamagne]

ChainImpl.get_tokens_balance("000030831178cd6a49fe446778455a7a980729a293bfa16b0a1d2743935db210da76" |> String.upcase(), [%{"token_address" => "000058C44C933FBD047BF694490371BB41DA037597FFD57970A1DE6832AF990B7752", "token_id" => 1}])

I expected it to return

%{
  %{
    "token_address" => "000058C44C933FBD047BF694490371BB41DA037597FFD57970A1DE6832AF990B7752",
    "token_id" => 1
  } => 0.0
}

insted of
%{}

[Neylix]

ChainImpl.get_tokens_balance("000030831178cd6a49fe446778455a7a980729a293bfa16b0a1d2743935db210da76" |> String.upcase(), [%{"token_address" => "000058C44C933FBD047BF694490371BB41DA037597FFD57970A1DE6832AF990B7752", "token_id" => 1}])

I expected it to return

%{
  %{
    "token_address" => "000058C44C933FBD047BF694490371BB41DA037597FFD57970A1DE6832AF990B7752",
    "token_id" => 1
  } => 0.0
}

insted of %{}

Done !