Rename RegisterTestFramework adapterFactory parameter

[nohwnd]

Rename adapterFactory parameter in Microsoft.Testing.Platform.Builder.ITestApplicationBuilder.RegisterTestFramework public api to frameworkFactory.

The naming is leaking the details of what we do for MSTest in the specific VSTest compatible implementation, but does not fit the generic interface.

This is a code breaking change for calls that use the name of the parameter.

[Youssef1313]

The break here is too minor and isn't binary break. TUnit, NUnit, and xUnit.net all are not using the parameter name. @nohwnd Should we just take this in 3.10/1.8?

[nohwnd]

sounds good.