[network] Feature: support static node

[0xcb9ff9]

Description

this PR add static node feature, static nodes configured for normal node not remove on runtime. unlike bootnode, node connections to static nodes is keep alive, if the connection is disconnected, node will actively try to reconnect static node (management connections is not affected by this PR)

command change

1. command dogechain genesis add --staticnode Flag
2. genesis file add staticnodes field
3. command dogechain peers add add --static Flag, dynamically add static nodes

genesis file simple:

{
.......
    "bootnodes": [
        "/ip4/10.5.0.15/tcp/1478/p2p/16Uiu2HAm7oonKfext8YgFCAMNWZKuXP2dpvnamCrN2VxjqTS54y3"
    ],
    "staticnodes": [
        "/ip4/10.5.0.15/tcp/1478/p2p/16Uiu2HAm7oonKfext8YgFCAMNWZKuXP2dpvnamCrN2VxjqTS54y3"
    ]
}

Changes include

• New feature (non-breaking change that adds functionality)

Checklist

• I have assigned this PR to myself
• I have added at least 1 reviewer
• I have added the relevant labels

Testing

• I have tested this code with the official test suite
• I have tested this code manually

Manual tests

1. create static nodes genesis file (1 boot node, 4 validator node, validator node configured boot node as a static node)
2. start up dogechain node
3. stop rpc node
4. check validator node is try reconnect rpc node

[codecov-commenter]

Codecov Report

Merging #280 (97f4c14) into dev (a840ee8) will decrease coverage by 3.32%.
The diff coverage is 40.51%.

@@            Coverage Diff             @@
##              dev     #280      +/-   ##
==========================================
- Coverage   51.21%   47.88%   -3.33%     
==========================================
  Files         117      127      +10     
  Lines       17525    19420    +1895     
==========================================
+ Hits         8975     9300     +325     
- Misses       7789     9329    +1540     
- Partials      761      791      +30     

Impacted Files	Coverage Δ
blockchain/storage/kvstorage/kvstorage.go	54.16% <ø> (+2.46%)	⬆️
chain/chain.go	28.69% <ø> (ø)
consensus/ibft/hooks.go	55.26% <ø> (ø)
consensus/ibft/pos.go	0.00% <0.00%> (ø)
helper/keccak/keccak.go	0.00% <ø> (ø)
helper/keccak/pool.go	0.00% <ø> (ø)
jsonrpc/debug_endpoint.go	36.08% <0.00%> (-0.76%)	⬇️
jsonrpc/net_endpoint.go	0.00% <0.00%> (ø)
network/bootnodes.go	100.00% <ø> (ø)
network/connections.go	98.07% <ø> (ø)
... and 108 more

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[DarianShawn]

Good work.
Only a few suggestions here

[DarianShawn]

One question.

[DarianShawn]

LGTM

[DarianShawn]

Thanks for the great job 🙌