Node list should not be hardcoded

[cryptoBeliever]

Currently, the default node list is hard-coded and we should change that.
The proposition is:

• use statistics service (currently ec2-34-222-209-211.us-west-2.compute.amazonaws.com:4001 but there will be dedicated DNS)
• currently, we have available endpoints:

/nodes
/nodes/<publicKey>

/nodesHostDetail
/nodeStats
/nodeHeightStats
/timeSeries/nodeCount

The endpoint list can change. We can add new endpoints (for example find by nodePublicKey could be very helpful on harvesting page) if it will be useful, we can add information to node info like if it supports harvesting and so on. Whatever will be help wallet.

• on harvesting view, we should allow user filter as is now but based on list from statistics service
• wallet nodes should be taken from node statistics service based on user region / locale (if possible without location permission)