Rename "Name" to "Slug" in project settings

### Problem Statement

The "project name" has been deprecated and "project slug" is used instead. 

### Solution Brainstorm

Update the [UI](https://github.com/getsentry/sentry/blob/master/static/app/data/forms/projectGeneralSettings.tsx#L53-L73) from "name" to "slug", for example:

```
Slug
A slug for this project.
```

Also during project creation. 

### Product Area

Projects - Project Details