Added the new switch parameter IdentifyTopFatFlows to Firewall Command

[Gizachew-Eshetie]

Description

Checklist

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[BethanyZhou]

Please name this parameter to IdentifyTopFatFlow to keep singularity requirement. See guideline here: https://github.com/Azure/azure-powershell/blob/main/documentation/development-docs/design-guidelines/parameter-best-practices.md#singularity

[Gizachew-Eshetie]

@BethanyZhou made changes and pushed. Please let me know if you have any more comments.

[BethanyZhou]

Could you provide sample output with following format
```output
{output}
```
If this example has no output, please fill it with None.

[Gizachew-Eshetie]

@BethanyZhou Added the output and pushed.

[BethanyZhou]

Looks good to me

[BethanyZhou]

/azp run azure-powershell - security-tools

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