Sander Postma authored Feb 25, 2022 and Ethan Reesor committed Feb 25, 2022

Closes AC-1063. Implements a connection manager that load-balances inter-network requests and monitors the status of other nodes.

Besides the connection manager it has changes to the subnet configuration in order to support node type. Also the subnet id is no longer in any key so we don't have the issue of matching subnet id's converted to lower-case by viper against subnet id's in i.e. networks.go.
I also made some minor name changes. I saw many different variations of subnet id, like

- subnet
- netName
- config.Network.ID (which is confusing with network names like "DevNet")

In places I worked on I changed it to subnetId because in the config we now have a struct Subnet with a field ID, but I can still rename things quickly if you can decide on a name that should be used consistently.

PS:
The CI pipeline passed https://gitlab.com/accumulatenetwork/accumulate/-/pipelines/476786526.
But when opening this PR I got I had to merge in the current develop and saw an earlier branch "Merge branch 'AC-1128' into 'develop'" from Dennis B failed so I'll have to see if the CI still passes now.