Add default Ensure value if not present

[FabienTschanz]

Pull Request (PR) description

This PR adds the default Ensure property value Present if it is not specified in the desired values and the resource is not a single instance element.

This Pull Request (PR) fixes the following issues

• Fixes Resources using Test-M365DSCParameterState do not support default Ensure value when using -DesiredValues $PSBoundParameters #5085

Task list

• Added an entry to the change log under the Unreleased section of the file CHANGELOG.md.
  Entry should say what was changed and how that affects users (if applicable), and
  reference the issue being resolved (if applicable).
• Resource parameter descriptions added/updated in the schema.mof.
• Resource documentation added/updated in README.md.
• Resource settings.json file contains all required permissions.
• Examples appropriately added/updated.
• Unit tests added/updated.
• New/changed code adheres to DSC Community Style Guidelines.

[FabienTschanz]

@Borgquite Do you have the time to test it with your usecase?

[ykuijs]

LGTM

[ykuijs]

Great solution! I will merge this PR when @Borgquite confirms this solution solves the issue

[Borgquite]

Will do! Give me a day or so.

[ykuijs]

Our next release is Wednesday next week, so a day is no problem 😉

[FabienTschanz]

@Borgquite Any updates on the testing? Wednesday is just around the corner, would be awesome if we could integrate that.

[Borgquite]

@FabienTschanz Hey - sorry, stuff got in the way (although I'm still happy to do this).

On paper it looks fine so if you want to integrate I can get back to you if it's still a problem. I'll see if I can get round to it this afternoon (but keep getting asked to come into meetings... sigh)