consider making cleos error messages more clear as to what endpoint is being used

[matthewdarwin]

It's not clear here what the "specified endpoint" is. Should the error tell us? (to those who know it is localhost:8888 of course)

Seems it might be nice to be able to have some cleos.ini file to tell it which endpoints to connect to for which type of thing. (I moved the net API onto a different port so cleos can't find it by default)

Our nodeos config.ini looks like this:

http-server-address = http-category-address
http-category-address = chain_ro,:8888
http-category-address = chain_rw,:8888
http-category-address = db_size,localhost:8889
http-category-address = net_ro,localhost:8889
http-category-address = net_rw,localhost:8889
http-category-address = producer_ro,localhost:8889
http-category-address = producer_rw,localhost:8889
http-category-address = snapshot,localhost:8889
http-category-address = prometheus,:9101