The dependency of DacPacs DacServices.Deploy() on Assembly.Location is erroneous when DLLs are embedded into EXE

Nobody has claimed this yet.

Hi!

We use "DACExtensions" in a desktop WPF application and embed all our dependencies (DLLs) into the resulting executable by the means of [Costura.Fody](https://github.com/Fody/Costura).

We've stumbled across an issue with `Microsoft.SqlServer.DacFx.x86` package newer than "150.4384.2" due to it retrieves the `Assembly.Location` path and uses it to construct a directory path. The `Assembly.Location` property returns an empty string when the assembly is embedded into an EXE.

Needless to say, it leads to the following exception:
```c
ERROR System.ArgumentException: The path is not of a legal form.
at System.IO.Path.NormalizePath(String path, Boolean fullCheck, Int32 maxPathLength, Boolean expandShortPaths)
at System.IO.Path.InternalGetDirectoryName(String path)
at Microsoft.SqlServer.Dac.DacServices.GetDeploymentContributorLoadPaths(IPackageSource packageSource, DacDeployOptions options) in f:\B\16847\6200\Sources\Product\Source\DeploymentApi\DacServices.cs:line 884
at Microsoft.SqlServer.Dac.DacServices.InternalDeploy(IPackageSource packageSource, Boolean isDacpac, String targetDatabaseName, DacDeployOptions options, CancellationToken cancellationToken, DacLoggingContext loggingContext, Action`3 reportPlanOperation, Boolean executePlan) in f:\B\16847\6200\Sources\Product\Source\DeploymentApi\DacServices.cs:line 809
at Microsoft.SqlServer.Dac.DacServices.Deploy(DacPackage package, String targetDatabaseName, Boolean upgradeExisting, DacDeployOptions options, Nullable`1 cancellationToken) in f:\B\16847\6200\Sources\Product\Source\DeploymentApi\DacServices.cs:line 743
```

May such a uses case with embedded libraries be considered for this package?

There is a very similar issue already reported:
microsoft/DacFx#402 "Extensions discovery issue in DacPac's DacServices.Deploy()"

Start with Microsoft.SqlServer.Dac.DacServices.Deploy and the GetDeploymentContributorLoadPaths call shown in the stack trace, then compare the embedded-assembly behavior described for Costura.Fody with the similar microsoft/DacFx#402 report. Done means DacServices.Deploy no longer fails with an illegal path when dependencies are embedded into a WPF executable.

Written by the indexing model from the issue text.