Done with a script by Tej; see
iris/iris!609 for details.

This is an alternative to !91, which was written prior to views. Using
the view CMRA we factor the implementation into purely algebraic library
and a logic-level wrapper. The logic-level wrapper exports resources
which seal away the underlying ownership and has theorems which handle
the ownership reasoning.

- This avoids confusion between `mnat` and `max_nat`. The `m` stands for `mono`.
- With `_mono` added, the `_auth` suffix in the algebra name no longer makes
  sense, so I removed it.
- This makes the names between the logic and the algebra-level library consistent.
- I also renamed `_frag` into `_lb` in the algebra-level library so as to make it
  consistent with the logic-level library.

Furthermore make the order of lemmas consistent and make the versions for the
fractions consistent.