Code fix: UseBuiltInTypeAlias

[sharwell]

Implement code fix for #54.

[pdelvo]

Visual Studio provides a built in solution to do this so I don't think we need a code fix for it.

[sharwell]

The Simplify Type Name code fix does handle this, but I noticed that the batch fixer it uses only operates on a single specific type of violation. For example, if you tell it to simplify UInt32, it will replace all instance of UInt32 with uint. However, it will not replace any instances of Int32 with int (you would have to invoke it separately for that case). It will also not replace any instance of System.UInt32 (the fully-qualified reference) with uint (also need to invoke it separately for this case).

I believe a general code fix could be implemented for SA1121 which covers all instances of this specific violation while ignoring all the other kinds of simplification which might be performed by the built-in Simplify Type Name code fix.

[sharwell]

I'm reopening this issue, because we could do a better job of implementing this rule than Visual Studio currently does. It's a relatively low priority issue though because we do have an alternative available.

[sharwell]

Fixed in #350.