Add high-stake validator warning#1318

ost-ptk wants to merge 3 commits into

developmake-software/casper-wallet:developfrom

WALLET-1275-as-a-casper-wallet-extension-i-should-warn-users-against-re-delegating-to-validators-with-significant-network-sharemake-software/casper-wallet:WALLET-1275-as-a-casper-wallet-extension-i-should-warn-users-against-re-delegating-to-validators-with-significant-network-shareCopy head branch name to clipboard