Edc-appointment

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- add SKIPPED_APPT appointment status to help handle routine
care where the next appointment may skip over the estimated
schedule.
- use settings attr to enable the use of appt_status=SKIPPED_APPT,
EDC_APPOINTMENT_ALLOW_SKIPPED_APPT_USING
- add signal to detect model that provides an appt date. Skip
over interim XXXX.0 appointments and update the target appointment
to the given date.

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- get default appt_type from func get_appt_type_default()
- add settings attribute EDC_APPOINTMENT_FORM_META_OPTIONS which can
override the default labels/help_text on the appontment
form
- declare appt_type list_data explicitly
- move appt_type field and method to model mixins

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- extend lower bound of next visit window if gap days exist and allowed
- use SiteModelAdminMixin
- use `update_fields` where possible
- validate `site` when creating appointnents

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- move functionality of methods next/previous to utils
- rename model method `visit` to `related_visit` to avoid conflict with edc-visit-schedule
model method `visit`

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- fix incorrectly formatted codename string passed to has_perm for unscheduled appts
- add pre-commit config
- expand testing matrix - add py3.10 dj4.0, dj4.1