Implement unmarshal Logs with jsoniter

[atingchen]

Description:
Now Traces And Metrics was converted to jsoniter, But Logs still uses jsonpb. Unmarshaler with jsoniter` will skip unknown fields instead of error

Link to tracking Issue: [https://github.com//pull/4986 ]
Testing:
unit test. construct a logs message, fill all the fields, use jsonpb marshal to json bytes, use jsoniter unmarshal to struct, test assert there are equal.

[codecov]

Codecov Report

Base: 92.01% // Head: 92.07% // Increases project coverage by +0.06% 🎉

Coverage data is based on head (b6d9a8f) compared to base (c512073).
Patch coverage: 97.93% of modified lines in pull request are covered.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #6021      +/-   ##
==========================================
+ Coverage   92.01%   92.07%   +0.06%     
==========================================
  Files         213      213              
  Lines       13232    13322      +90     
==========================================
+ Hits        12175    12266      +91     
  Misses        838      838              
+ Partials      219      218       -1     

Impacted Files	Coverage Δ
pdata/plog/json.go	98.18% <97.87%> (+13.18%)	⬆️
pdata/internal/json/attribute.go	100.00% <100.00%> (ø)

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[bogdandrutu]

Unnecessary func called once.