Update .asmdef files also when referencing precompiled .dlls

**Description:**
The new feature for referencing asmdefs when adding references in Rider is great! However, it doesn't currently handle referencing precompiled dlls. This should
* Ensure that the `overrideReferences` property in the asmdef file is set to `true`
* Add the referenced dll to `precompiledReferences` array in the asmdef

**Example reproduction:**
1. Add the `com.unity.test-framework` package (1.X version, 2.X preview contains a bug that changes behaviour here)
2. Write code that references NUnit, e.g. `Assert.That(null, Is.Null);`
3. Instruct rider to reference the NUnit assembly

**Expected result:**
The .asmdef contains
```
"overrideReferences": true,
"precompiledReferences": [
"nunit.framework.dll"
],
```

**Actual result:**
The .asmdef does not change.

**Notes:**
I also found a TODO comment in your code related to this, but thought I'd express my interest and let others know this is not a bug by writing an issue :)

Start at the TODO comment related to precompiled assembly references and trace the Rider action that updates asmdef references. Reproduce the NUnit example with com.unity.test-framework, then verify that the asmdef sets overrideReferences to true and includes nunit.framework.dll in precompiledReferences.

Written by the indexing model from the issue text.