fix/centralize ag 'create any database' perms

[lowlydba]

• Not needed in New-DbaAvailabilityGroup since it is handled in both Replica and Database AG Adders
• Utilize Grant-DbaAgPermission as the route to do this perm via SMO, and only if automatic seeding
• Fix Grant-DbaAgPermission parameter parsing so it actually works

Type of Change

• Bug fix (non-breaking change, fixes Add-DbaAgReplica doesn't add req 'NT AUTHORITY\SYSTEM' perms #8178
• New feature (non-breaking change, adds functionality, fixes # )
• Breaking change (effects multiple commands or functionality, fixes # )
• Ran manual Pester test and has passed (.\tests\manual.pester.ps1)
• Adding code coverage to existing functionality
• Pester test is included
• If new file reference added for test, has is been added to github.com/dataplat/appveyor-lab ?
• Unit test is included
• Documentation
• Build system

Purpose

Followup from #8181
Fixes & standardizes the create database permission required by AGs for automatic seeding.

Approach

• Make Grant-DbaAgPermission use SMO
• Make all other functions use Grant-DbaAgPermission
• Remove the granting from New-DbaAgAvailabilityGroup since it calls both the Add-Replica and Add-Database functions already

Commands to test

• Add-DbaAgDatabase
• New-DbaAvailabilityGroup
• Add-DbaAgReplica
• Grant-DbaAgPermission

[andreasjordan]

Thanks for the pull request, looks good. Will do some more testing when both AG related PRs are merged into development.

[potatoqualitee]

Thank you both 🙇🏼

[andreasjordan]

Sorry, we have an issue with this:

I will have a look, please do not release yet, @potatoqualitee

[andreasjordan]

When Add-DbaAgReplica is started from New-DbaAvailabilityGroup, then the AG is still in State Creating - and thus it can not be altered. So we have to set this inside of Add-DbaAgReplica only if the AG is already created to support adding new nodes to the AG. But this has also be set inside of New-DbaAvailabilityGroup after creating the AG.

Will code this now...

[andreasjordan]

Ok, fixed the issue, but will do more tests...

[andreasjordan]

Opened #8185 for that. Tested in my Windows Cluster with Automatic Seeding. Created a two node AG with New-DbaAvailabilityGroup and one database, then used Add-DbaAgReplica to add a third replica. Database was automatically created on the third replica because of Automatic Seeding. So I think this work now.