Update `planet data stats` CLI and python API commands to match `search`

[cholmes]

Expected behavior
UI of planet data stats and planet data search should be similar.

Actual behavior (describe the problem)
planet data search has filter as an option (--filter), planet data stats has interval and filter as arguments.

Proposed Solution

Update stats CLI and python API commands to match search. Expected command would be planet data stats PSScene --filter - --interval day (assuming a filter is piped in).