This PR continues the refactoring of the front end code for dashboards.
The main points are:
- Extracts the `ActionBox` component that we used in a lot of places.
There were some minor differences between the various incarnations, so
this also better aligns them.
- Extract other components (`AskOwnerToAddYouToTheirProject`,
`YourAdmins`)
- Move the `NeutralCircleContainer` into `SharedComponents`
- Delete the separate no content grid (this is now handled in projects
instead)
- extract my projects grid contents into a single function so that it's
easier to understand what content you get for what states
Here's all the states side by side:
