Fix token supply on mint

[ghost]

Purpose

On mint events an internal object CisEventTokenAddedUpdate was created in EventLogHandler. This was later used to update the total token supply in class EventLogWriter on method CreateTokenAddedCmd.

However the SQL query did nothing if the token already existed.

INSERT INTO graphql_tokens(contract_index, contract_sub_index, token_id, total_supply)
                VALUES (@ContractIndex, @ContractSubIndex, @TokenId, @TotalSupply)
                ON CONFLICT ON CONSTRAINT graphql_tokens_pkey
                DO NOTHING";

Because of this, whenever token was minted on id’s which already existed, the total amount wouldn’t increase.

OBS: The total token supply data is currently corrupted and a separate PR with a clean up job will be created.

Changes

Object CisEventTokenAddedUpdate and method CreateTokenAddedCmd has been removed, such that now CisEventTokenAmountUpdate is used for both mint and burn events. The SQL used updates the total supply in case token id already exists.

INSERT INTO graphql_tokens(contract_index, contract_sub_index, token_id, total_supply)
                VALUES (@ContractIndex, @ContractSubIndex, @TokenId, @AmountDelta)
                ON CONFLICT ON CONSTRAINT graphql_tokens_pkey
                DO UPDATE SET total_supply = graphql_tokens.total_supply + @AmountDelta

Checklist

• My code follows the style of this project.
• The code compiles without warnings.
• I have performed a self-review of the changes.
• I have documented my code, in particular the intent of the
  hard-to-understand areas.
• (If necessary) I have updated the CHANGELOG.