Install clean copy of distro under new name

**Is your feature request related to a problem? Please describe.**
I want to easily install multiple copies of one distribution under different names. For example I'd like a DebianA for one project, and a DebianB for another project.

**Describe the solution you'd like**
I'd like for wsl --install to have an additional commandline argument that lets me specify a name. Something like:

```
wsl --install -d Debian --name DebianA
wsl --install -d Debian --name DebianB
```

**Describe alternatives you've considered**
There's a workaround here - https://fourco.nl/blogs/duplicate-a-linux-distro-under-wsl2/ - which boils down to:
```
wsl --install -d Debian
wsl --export Debian debian_stock.tar
wsl --import DebianA .\DebianA debian_stock.tar
wsl --import DebianB .\DebianB debian_stock.tar
```
But this is inconvenient if I want an automated way to create a *stock* copy. I'd have to delete my real 'Debian', install a fresh copy, and then carry out the export+import+import steps.

Start with the existing `wsl --install` command and compare its behavior with the `--export` and `--import` workflow described in the issue. The change is done when `--install -d Debian --name DebianA` and a second differently named copy provide automated clean installations without requiring the workaround.

Written by the indexing model from the issue text.