Extract option - replace DBName in 3-part naming with $(DatabaseName) variable

Nobody has claimed this yet.

- SqlPackage or DacFx Version: 162.5.57.1
- .NET Framework (Windows-only) or .NET Core:
- Environment (local platform and source/target platforms):
.NET SDK:
Version: 9.0.203
Commit: dc7acfa194
Workload version: 9.0.200-manifests.9df47798
MSBuild version: 17.13.20+a4ef1e90f

Runtime Environment:
OS Name: Windows
OS Version: 10.0.17763
OS Platform: Windows
RID: win-x64
Base Path: C:\Program Files\dotnet\sdk\9.0.203\

**Steps to Reproduce:**

1. create a trigger in an Azure SQL database, using a three-part name on the table that self-references the name of the database. So it would be (within the AdventureWorks database) "create trigger dbo.my_trigger_here on "AdventureWorks"."dbo"."mytablehere"..." (we can also duplicate it with "create trigger dbo.my_trigger_here on [Adventureworks].[dbo].[mytablehere]..." The trigger is valid and works. It's not using an external reference so it's legitimate.
2. use SQLPACKAGE to EXTRACT it with VerifyExtraction=true (it didn't extract because of errors, I had to use VerifyExtraction=false, but this may simplify repro)
3. sqlpackage /Action:Extract /SourceServerName:myazsqldb.database.windows.net /SourceDatabaseName:mydbname /SourceUser:myusername /SourcePassword:"mypassword" /TargetFile:myservername-mydbname /p:ExtractTarget=ObjectType /p:ignoreuserloginmappings=false /DiagnosticsFile:20250416_1319.log /p:ExtractAllTableData=false /p:VerifyExtraction=false

**Did this occur in prior versions? If not - which version(s) did it work in?**
No idea - I'm just now trying to set up CI/CD.

(DacFx/SqlPackage/SSMS/Azure Data Studio)
Unsure which, I think DacFx because I'm having the same problem trying to BUILD it in ADS, BUILD it in VS Code (SDK-style database projects), Visual Studio Preview (BUILD from an "SDK-style database project (preview)" with the code) and EXTRACTing with SQLPackage.

Start with the SqlPackage/DacFx Extract path for trigger definitions using three-part table names, and reproduce the case with VerifyExtraction enabled and disabled. Compare the generated result for a self-referencing database name such as AdventureWorks; done means the DBName portion is replaced with the $(DatabaseName) variable and extraction/build succeeds.

Written by the indexing model from the issue text.