Pass coverlet codebase in runsettings for inproc data collector initialization

[vagisha-nidhi]

Description

Initilization of inproc coverlet collector today needs passing the datacollector extensibility in TestPluginCache. This enables the InProcDataCollectionExtensionManager to be able to find the datacollector in all datacollector extension paths if inproc datacollector codebase path is not an absolute path.
We should directly add this path in runsettings ideally since vstest.console.exe is aware of all datacollector extension paths.
This will remove unnecessary coverlet specific changes from

vstest/src/Microsoft.TestPlatform.CrossPlatEngine/Client/ProxyExecutionManager.cs

Line 272 in ca987de

extensions = extensions.Concat(TestPluginCache.Instance.GetExtensionPaths(ProxyExecutionManager.CoverletDataCollector, true)).ToList();

and
https://github.com/microsoft/vstest/blob/master/src/Microsoft.TestPlatform.TestHostProvider/Hosting/DotnetTestHostManager.cs#L321

cc: @AbhitejJohn @MarcoRossignoli

[MarcoRossignoli]

I'm working on this, I'll let you know.
I found also a new small bug, I'll open new issue.
Feel free to assign to me if you want.

[vagisha-nidhi]

Thanks @MarcoRossignoli 👍