Add several metrics to measure storage sub system.

[hanahmily]

• Update the CHANGES log.

[codecov-commenter]

Codecov Report

Merging #266 (218a266) into main (09925ff) will decrease coverage by 0.34%.
The diff coverage is 38.70%.

@@            Coverage Diff             @@
##             main     #266      +/-   ##
==========================================
- Coverage   46.87%   46.54%   -0.34%     
==========================================
  Files          89       89              
  Lines        9112     9267     +155     
==========================================
+ Hits         4271     4313      +42     
- Misses       4441     4549     +108     
- Partials      400      405       +5     

Impacted Files	Coverage Δ
banyand/tsdb/indexdb.go	5.61% <0.00%> (-1.63%)	⬇️
banyand/tsdb/scope.go	0.00% <0.00%> (ø)
pkg/index/lsm/lsm.go	78.26% <0.00%> (-7.46%)	⬇️
pkg/meter/meter.go	45.00% <0.00%> (-2.37%)	⬇️
pkg/timestamp/scheduler.go	0.00% <0.00%> (ø)
banyand/tsdb/shard.go	55.38% <22.91%> (-11.51%)	⬇️
banyand/tsdb/block.go	53.95% <30.76%> (-3.81%)	⬇️
banyand/liaison/grpc/server.go	72.12% <50.00%> (-3.75%)	⬇️
banyand/tsdb/seriesdb.go	48.27% <66.66%> (+0.16%)	⬆️
pkg/index/inverted/inverted.go	70.06% <80.00%> (-0.49%)	⬇️
... and 5 more

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