This task is to track the remaining work to do about an orchestrator module. That
orchestrator would be the missing cog in charge of actually regularly scheduling origins
of a given type according to the scheduler metrics reported.
Orchestrator of scheduler runner next-gen, the algo would be something like:
```
for each visit type:
- queue filled-in: monitored, when under a given threshold event is reached,
this triggers a fill-in the void state. goto "fill-in the void state"
- fill-in the void state:
for each policy (per ratio [1]) for that visit type:
- fetch origins and schedule
- continue until threshold is reached or policy has no results
- when threshold is reached, goto "queue filled-in"
```
[1] Ratio repartition could be:
```
|----------------------------------------------------------------+-----------------------------------+-------|
| visit_type | scheduling policies | ratio |
|----------------------------------------------------------------+-----------------------------------+-------|
| package-loader: archive, cran, debian, npm, nixguix, pypi, ... | already_visited_order_by_lag | 50 |
| | never_visited_oldest_update_first | 50 |
|----------------------------------------------------------------+-----------------------------------+-------|
| git, svn, hg | already_visited_order_by_lag | 49 |
| | never_visited_oldest_update_first | 49 |
| | origins_without_last_update | 2 |
|----------------------------------------------------------------+-----------------------------------+-------|
```