Nuget dependencies not found when using reflection

### Steps to reproduce

I have a project P1 containing a class C1 and C2. I publish it as a nuget package P1.

In an another solution, I create a console project P2, add a nuget reference to P1.
The code in the project P2 tries to find by reflection C1.

From Visual Studio (2017 & 2019), I start the P2 project (F5).

### Expected behavior

I should find the type C1.

### Actual behavior

C1 and the P1 assembly does not exists.

If I publish the project, the P1 dll is present and the app works fine.

Still in Visual Studio, if I had a direct reference to C2 in the P2 project, then I can find C1 by reflection.

Visual Studio (msbuild) seems to make 'optimizations' and does not provide correctly the nuget dependencies if they are only used by reflection.

### Environment data
`msbuild /version` output:

```
C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise>msbuild /version
Microsoft (R) Build Engine version 16.3.1+1def00d3d for .NET Framework
Copyright (C) Microsoft Corporation. All rights reserved.

16.3.1.50202
```

OS info: