Allow Changing DACPAC Name

**Is your feature request related to a problem? Please describe.**

I have two sqlproj files that deploy to Azure and onprem respectively. The Azure version can't support certain things, such as service brokers, so those are omitted. The problem is that both versions share almost all files in common and it's not clear from a glance how they are different.

To avoid confusion, rather than maintain two sqlproj files, I have converted them to a single sqlproj with a `` conditional to set the `DSP` and the files to exclude when trying to produce an Azure compatible DACPAC. The one thing I can't seem to do is change the name of the DACPAC produced as neither the `Name` nor the `AssemblyName` properties have an effect, it just uses whatever the filename is.

I've Googled and come up empty so hopefully I haven't missed something obvious.

**Describe the solution you'd like**

Provide the option to override the default name of the dacpac produced using the `Name` property or expose a `DacpacName` property that controls the name used.

The issue names no source files or tests. Start by locating the DACPAC output naming logic for SQL projects and how Name and AssemblyName are handled; done means a documented property can override the generated DACPAC filename, including when the project uses conditional Choose settings.

Written by the indexing model from the issue text.