Calculate the maximal and minimal rank possible for each node
in any ranking that is in accordance with the partial ranking `P`

.

`rank_intervals(P)`

- P
A partial ranking as matrix object calculated with neighborhood_inclusion or positional_dominance.

An object of type netrankr_interval

Note that the returned `mid_point`

is not the same as the expected
rank, for instance computed with exact_rank_prob.
It is simply the average of `min_rank`

and `max_rank`

. For exact rank probabilities
use exact_rank_prob.

```
P <- matrix(c(0, 0, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, rep(0, 10)), 5, 5, byrow = TRUE)
rank_intervals(P)
#> node:V1 rank interval: [1, 2] mid point: 1.5
#> node:V2 rank interval: [1, 4] mid point: 2.5
#> node:V3 rank interval: [2, 4] mid point: 3
#> node:V4 rank interval: [3, 5] mid point: 4
#> node:V5 rank interval: [3, 5] mid point: 4
```