Disallow duplicate dimension sets

[markkuhn]

Related issues:

• Disallow duplicate dimension sets. aws-embedded-metrics-node#20
• fix: prevent putDimensions from storing duplicate dimensions aws-embedded-metrics-node#104
• fix: prevent putDimensions from storing duplicate dimensions aws-embedded-metrics-java#88
• Disallow duplicate dimension sets aws-embedded-metrics-dotnet#31

Currently duplicate dimension sets are being allowed.
Example:

metrics.put_dimensions({"Region": "us-east-1"})
metrics.put_dimensions({"Region": "us-east-2"})

This creates:

"Dimensions": [
  [
    "LogGroup",
    "ServiceName",
    "ServiceType",
    "Region"
  ],
  [
    "LogGroup",
    "ServiceName",
    "ServiceType",
    "Region"
  ]
]

When it should be:

"Dimensions": [
  [
    "LogGroup",
    "ServiceName",
    "ServiceType",
    "Region"
  ]
]

[gordonpn]

Should there be an issue for the dotnet library as well?

[markkuhn]

@gordonpn It is indeed an issue in the dotnet library as well. Creating an issue for it.