Update the resource group tag filter to use server side odata query

[hamidtirmizi]

Description

Get Resource Group cmdlet currently performs client side filtering of resource group, and it has a logic bug.

This PR removes client side filtering, and uses the now-supported server side filtering based on odata query.

Checklist

• I have read the Submitting Changes section of CONTRIBUTING.md
• The title of the PR is clear and informative
• The appropriate ChangeLog.md file(s) has been updated:
  • For any service, the ChangeLog.md file can be found at src/{{SERVICE}}/{{SERVICE}}/ChangeLog.md
  • A snippet outlining the change(s) made in the PR should be written under the ## Upcoming Release header -- no new version header should be added
• The PR does not introduce breaking changes
• If applicable, the changes made in the PR have proper test coverage
• For public API changes to cmdlets:
  • a cmdlet design review was approved for the changes in this repository (Microsoft internal only)
  • the markdown help files have been regenerated using the commands listed here

[wyunchi-ms]

Hi @hamidtirmizi how long does the test expect to cost? Do you need any help?

Wrong operation

[hamidtirmizi]

Tests added. PR ready for review.

[Tiano2017]

[hamidtirmizi]

@wyunchi-ms please take a look

[Geraint87]

Can we have an example in the docs please? (Or even just here, to get started). I still don't think Get-AzResourceGroup with multiple tags works, or if so, I don't know how.
Example:
Get-AzResourceGroup -Tag @{AppId = "1"; Environment = "P"};
Response:
Invalid tag format. Expect @{tagName = $null} or @{tagName = "tagValue"}
Thanks!