Provide more reference material (cmdlet, documentation) on MaxSizeBytes property

## Description of the new feature

AFAICT there is no clear algorithm that indicates what values are allow for MaxSizeBytes on most Az.Sql single database manipulating commandlets or AzureRM apis.

In reviewing:

https://docs.microsoft.com/en-us/sql/t-sql/statements/create-database-transact-sql?view=azuresqldb-current&preserve-view=true&tabs=sqlpool

and

https://docs.microsoft.com/en-us/rest/api/sql/2020-11-01-preview/databases/create-or-update

and

https://docs.microsoft.com/en-us/powershell/module/az.sql/new-azsqldatabase?view=azps-6.4.0

I don't see any formula to get valid values for the MaxSizeBytes property other than:

* Deploy using portal
* Export template and observe maxsizebytes
* Use that maxsizebytes

There used to be a MaxSizeGB but that was removed - I'm also not sure that would help in all cases.

There is some evidence Microsoft has had some challenges keeping this in order on their end based on documentation that became invalid:

https://github.com/MicrosoftDocs/azure-docs/issues/66298

Let me know if I can provide more info, I have searched across many forums and even asked on the PowerShell Discord/Slack Azure channel for advice (still waiting to receive an answer there).

## Proposed implementation details (optional)

I think documentation is reasonable - if you prefer to migrate this to MicrosoftDocs or tell me to open an issue there, that's fine by me. However, if there was some way to also have the values assignable in portal be translatable via cmdlet that could be run from powershell, that'd also be great. That or an API call? I'm open to anything. I'm even open to just having an explanation here.