Rename `all?`, `any?` and `empty?` to `all`, `any` and `is-empty` for sake of simplicity and consistency.
- More understandable for newcomers, that these commands are no special to others.
- `?` syntax did not really aprove readability. For me it made it worse.
- We can reserve `?` syntax for any other nushell feature.
* commands: any? all?
We can check if `any` (or `all`) rows of tables match predicates.
Small `all?` example: Given the following table with `services` running:
```
> echo [[status]; [UP] [UP]]
───┬────────
# │ status
───┼────────
0 │ UP
1 │ UP
───┴────────
```
We can ask if all services are UP, like so:
```
> echo [[status]; [UP] [UP]] | all? status == UP
true
```
* Fix any? signature.
