Configurable logging

[moisses89]

What is needed?

Every time that Debug is enabled, is enabled in all the code and is hard to follow sometimes.
With this enhancement we should be able to enable DEBUG for some parts of code, as for example to everything related with ERC20 indexer, and leave the rest in INFO level.

Log groups proposal

ERC20_721_INDEXER_LOG_LEVEL
PROXY_FACTORY_INDEXER_LOG_LEVEL
SAFE_EVENTS_INDEXER_LOG_LEVEL
INTERNAL_TX_INDEXER_LOG_LEVEL
API_LOG_LEVEL (all the endpoints)
BALANCES_API_LOG_LEVEL
MESSAGES_API_LOG_LEVEL
ALL_TRANSACTIONS_API_LOG_LEVEL

Proposed solution

Django logging is configurable and we can define different environment variables to enable just DEBUG in some parts of the service. For example:

#ERC20_LOGGER
       "safe_transaction_service.history.indexers.erc20_events_indexer": {
            "level": env("ERC20_INDEXER_LEVEL", default="INFO")
        },
        "safe_transaction_service.history.tasks.index_erc20_events_task": {
            "level": env("ERC20_INDEXER_LEVEL", default="INFO")
        },

Just remark that if DEBUG is enabled in general way all the parts of the code should be log level DEBUG