Enhance logs readability per exchange

[sjanel]

Currently the logs don't always specify which exchange they are related to.
It's sometimes difficult to understand what's happening especially with the coming support of parallel requests.

What about adding a sub subject with the ExchangeName in spdlog ?

For instance, from this (currently):

[2023-08-11 17:54:46.358] [info] GET https://api.upbit.com/v1/accounts
[2023-08-11 17:54:46.358] [info] GET https://api.kucoin.com/api/v1/accounts

to something like:

[2023-08-11 17:54:46.358] [info] [upbit_marc] GET https://api.upbit.com/v1/accounts
[2023-08-11 17:54:46.358] [info] [kucoin_brian] GET https://api.kucoin.com/api/v1/accounts