Offer a better class file duplication / rename method

[S0und]

Visual Studio Version: 16.7.7

Summary: There are times when you already have a class or report and you need a pretty similar file. So duplicating the already existing one and changing it is much faster, then recreating a new one from scratch. The problem is that VS doesn't offer a nice way to duplicate a file with a new given name. If you copy a file and paste it into the same folder, VS detect the file duplication and the pasted file will automatically gets a " - Copy" file name suffix. The problem is VS in this state unable to refactor the filename and it's class and constructor name. Which by convention all should be the same.

I would guess this is an expected behavior, since this is how Windows handles file duplication. So if you copy a file and paste it into the same folder - without any warning - the new file will get a " - Copy" suffix. You only get the file duplication prompt window if you copy files between folders, but not in the same folder.

Steps to Reproduce:

https://giant.gfycat.com/LinearHopefulAlabamamapturtle.webm

Expected Behavior:

Here's how Intellij handles the same situation:
https://giant.gfycat.com/IgnorantDiscreteAustraliankestrel.webm

1. it doesn't allow file duplication AND doesn't creates a new file automatically. So it doesn't creates a new file and leaves it in a "broken state" for further file name refactoring.

2. When you give it a new and valid file name, the file's class and it's constructor are properly named after the file.

User Impact:

My issue is that there is no way to duplicate a file in a clean manner in VS. You can rename the file's name (+designer name if it has one), but the actual file content (class, constructor) needs to be manually edited.

[jinujoseph]

cc @ryzngard