Extract New-ResourceGroup private command for reuse

[flanakin]

🛠️ Description

Extract the new RG creation from Deploy-FinOpsHub to reuse in other commands.

📋 Checklist

🔬 How did you test this change?

• 🤏 Lint tests
• 🤞 PS -WhatIf / az validate
• 👍 Manually deployed + verified
• 💪 Unit tests
• 🙌 Integration tests

🙋‍♀️ Do any of the following that apply?

• 🚨 This is a breaking change.
• 🤏 The change is less than 20 lines of code.

📑 Did you update docs/changelog.md?

• ✅ Updated changelog (required for dev PRs)
• ➡️ Will add log in a future PR (feature branch PRs only)
• ❎ Log not needed (small/internal change)

📖 Did you update documentation?

• ✅ Public docs in docs (required for dev)
• ✅ Internal dev docs in src (required for dev)
• ➡️ Will add docs in a future PR (feature branch PRs only)
• ❎ Docs not needed (small/internal change)

[flanakin]

Suggested change

	.EXAMPLE
	New-ResourceGroup -WhatIf
	Shows what would happen if the command runs without actually running it.
	.DESCRIPTION
	The New-ResourceGroup command performs any initialization tasks required for a resource group contributor to be able to deploy a FinOps hub instance in Azure, like registering resource providers. To view the full list of tasks performed, run the command with the -WhatIf option.
	.DESCRIPTION
	The New-ResourceGroup command performs any initialization tasks required for a resource group contributor to be able to deploy a FinOps hub instance in Azure, like registering resource providers. To view the full list of tasks performed, run the command with the -WhatIf option.
	.EXAMPLE
	New-ResourceGroup -WhatIf
	Shows what would happen if the command runs without actually running it.

[flanakin]

Add parameters to the docs

[helderpinto]

Adding parameters...

Suggested change

	.PARAMETER Name
	Specifies a name for the resource group. The resource group name must be unique in the subscription. If a resource group that has that name already exists, the command prompts you for confirmation before replacing the existing resource group.
	.PARAMETER Location
	Specifies the location of the resource group.
	.PARAMETER Tags
	Key-value pairs in the form of a hash table. For example: @{key0="value0";key1=$null;key2="value2"}