Sync aws sdk attributes with semantic conventions

[nemoshlag]

Solves #3521 for DynamoDB and AWS SDK.

Making AWS SDK attributes consistent with RPC clients:

1 Rename "aws.operation" attribute to "rpc.method"
2 Rename "aws.service" attribute to "rpc.service"
3 Add "rpc.system" attribute and set it to "aws-api" value

According to semconv

[codecov]

Codecov Report

Merging #3617 (2a766a8) into main (5e79d2a) will increase coverage by 0.0%.
The diff coverage is 100.0%.

Additional details and impacted files

@@          Coverage Diff          @@
##            main   #3617   +/-   ##
=====================================
  Coverage   70.0%   70.0%           
=====================================
  Files        147     147           
  Lines       6960    6963    +3     
=====================================
+ Hits        4874    4877    +3     
  Misses      1961    1961           
  Partials     125     125           

Impacted Files	Coverage Δ
...git.luolix.top/aws/aws-sdk-go-v2/otelaws/attributes.go	82.3% <100.0%> (+2.3%)	⬆️
...tation/github.com/aws/aws-sdk-go-v2/otelaws/aws.go	94.2% <100.0%> (+<0.1%)	⬆️