Pii-extract-base

* Config changes
- allow specification of plugin load order
- set a default order for known plugins
- allow task custom configuration:
- when building tasks, pass along the config to the task constructor
- can deactivate context filter via task config (will also remove it from
the `task_info.method` field)
* API improvements
- return task method in task_info()
- allow specification of plugins to load in task_info script
- allow default format in piic_format()
* Behavior changes:
- improved error reporting on regex compile exceptions
- improved debug messages
- use add_process_stage() from pii-data 0.5.0
* fixes
- correctly add task "method" info field when building a task object
- ensure process stage is not duplicated
- fix in task_info script
- filter out tasks by language, also for multiclass descriptors
- updated plugin entry point selection for Python >= 3.10

* fix: corrected debug output for context

* fix: must export class in pii_extract.api
* added debug output when executing tasks

* Added `languages` argument to PiiProcessor, to restrict the pre-collection
of tasks
* Ensure a task is not built twice in the same PiiTaskCollection, if it's for
the same language
* fixed task_info api call & script

* PiiCollectionBuilder modified, adding methods add_detector_fields() &
add_collection()
* PiiBaseTask: add task-level method if pii-level method is not available
* updated for pii-data v. 0.4.0
* refactor a number of modules (**note: breaking changes**)

* removed cache of built tasks: now they are rebuilt again if included
in lists (each task decides if it caches something)
* fixed regex group detection (when there are initial unmatched groups)
* fix: do not expand the language list in BaseTaskCollector.gather_tasks()
(would cause to execute the gather process twice)
* added more logging lines