Add a new register-task-types cli that will create missing task-type entries in the
scheduler according to:
- only create missing task-types (do not update them), but check that the
backend_name field is consistent,
- each SWHTask-based task declared in a module listed in the 'task_modules'
plugin registry field will be checked and added if needed; tasks which name
start wit an underscore will not be added,
- added task-type will have:
- the 'type' field is derived from the task's function name (with underscores
replaced with dashes),
- the description field is the first line of that function's docstring,
- default values as provided by the swh.lister.cli.DEFAULT_TASK_TYPE (with
a simple pattern matching to have decent default values for full/incremental
tasks),
- these default values can be overloaded via the 'task_type' plugin registry
entry.
For this, we had to rename all tasks names (eg. `cran_lister` -> `list_cran`).
Comes with some tests.
8d9deeb8f8