Add a confirmation step to interactive CLI commands

This could be simple. Something like this for `edgedb project init`:
```
Creating a new project named with EdgeDB version . Proceed? (Y/n)
```

and for `edgedb instance create`:
```
Creating a new instance named with EdgeDB version . Proceed? (Y/n)
```

I do notice in running `project init` that we have a confirmation step at the beginning of the process:
```
Do you want to initialize a new project? [Y/n]
```

It seems a bit odd to bookend the process with confirmations on either side. I understand we probably do it at the beginning because we haven't found an existing project to initialize. Maybe instead of a confirmation step at the beginning, we could just log out what we've found:
```
No edgedb.toml file found. Creating a new project...
```

The user now understands why they are going through the interactive prompts for a new project. They can sigint if this isn't what they want or they can always respond `n` to the confirmation at the end if they decide then they didn't want to create a new project.