[metrics] Use a new metric for sync select head and rename networkp2p metrics

[jolestar]

1. 新增 chain_select_head_total， 保证 chain_block_connect_total 的每种类型总和是 100%，方便出饼图。
2. 重命名部分 networkp2p 的 metrics。

[codecov]

Codecov Report

Merging #2987 (0448e5a) into master (17a440e) will increase coverage by 0.06%.
The diff coverage is 11.12%.

❗ Current head 0448e5a differs from pull request most recent head 391ca23. Consider uploading reports for the commit 391ca23 to get more accurate results

@@            Coverage Diff             @@
##           master    #2987      +/-   ##
==========================================
+ Coverage   33.33%   33.39%   +0.06%     
==========================================
  Files         515      515              
  Lines       45688    45692       +4     
  Branches    20831    20833       +2     
==========================================
+ Hits        15225    15253      +28     
- Misses      16041    16153     +112     
+ Partials    14422    14286     -136     

Flag	Coverage Δ
unittests	33.39% <11.12%> (+0.06%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
sync/src/block_connector/write_block_chain.rs	30.00% <0.00%> (+1.00%)	⬆️
sync/src/block_connector/metrics.rs	30.31% <16.67%> (-6.73%)	⬇️
rpc/server/src/module/mod.rs	0.00% <0.00%> (-16.84%)	⬇️
vm/types/src/transaction/error.rs	3.93% <0.00%> (-15.68%)	⬇️
network-rpc/core/src/lib.rs	23.53% <0.00%> (-5.88%)	⬇️
cmd/starcoin/src/cli_state.rs	47.37% <0.00%> (-5.26%)	⬇️
cmd/starcoin/src/dev/tests.rs	14.44% <0.00%> (-4.12%)	⬇️
types/src/startup_info.rs	64.23% <0.00%> (-3.66%)	⬇️
txpool/src/pool/listener/tests.rs	10.91% <0.00%> (-3.63%)	⬇️
... and 73 more

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