* [NOD-322] Make database.DB a function
* [NOD-322] Move context to be the first parameter in all functions
* [NOD-322] Set db to nil on database.Close()
* [NOD-322] Tidy go.mod/go.sum
* [NOD-322] Use http package const + message for StatusInternalServerError
* [NOD-303] Implement get transaction by id for api server
* [NOD-303] Make routeParamTxID a constant
* [NOD-303] Change database is not current error.
* [NOD-303] Add ID to TransactionInput and TransactionOutput models
* [NOD-303] Change transactions_outputs table name to transaction_outputs and transactions_inputs to transaction_inputs
* [NOD-303] Add json annotations to transaction response types
* [NOD-303] Split server package
* [NOD-303] Add GetTransactionByHashHandler
* [NOD-303] Add comments to exported functions and variables
* [NOD-303] Put response types in a separate file
* [NOD-303] Rename functions
