Need to remove the dependency to CommonServiceLocator package

[carldebilly]

Bug Report

Current behavior

Right now there's a strong dependency to CommonServiceLocator package defined
in the csproj:

https://github.com/nventive/Uno.Core/blob/5aecd4909faeacb522fb303cb100c9de14eabb06/src/Uno.Core/Uno.Core.csproj#L34

This dependency can conflict with higher level frameworks implementing the CommonServiceLocator of a more recent version.

Since Uno.Core is forcing a pretty old version, it's expected those conflicts can occurs.

Expected behavior

The code should be refactored to completely remove this dependency.

[MakanWG]

Just had the issue after referencing the latest version of MVVMLight which uses CommonServiceLocator 2.0.5 while Uno.Core still uses 1.3.0.
I downgraded MVVMLight to make it work. Is this the recommended solution until this item is adressed ? @MatFillion

[carldebilly]

@MakanWG This reference could be removed totally. I think it's used for logging, but we can (and should) use something else for that.

[jeromelaban]

It can be replaced, but it will make for a binary breaking change. We'll be doing a set of breaking changes like those along with the changes in AndroidX (which is going to force a whole set of other breaking changes)

[weitzhandler]

Related: #69.