fix ulid namespace and migrations issues

[sainak]

• resolve migration issues with availibilty duplicates
• modify the ulid implementation to use python-ulid to avoid namespace conflicts
• update migrations

[codecov]

Codecov Report

Attention: 147 lines in your changes are missing coverage. Please review.

Comparison is base (fcea22e) 61.65% compared to head (fe69be0) 61.88%.
Report is 5 commits behind head on master.

Files	Patch %	Lines
care/facility/tasks/location_monitor.py	29.41%	24 Missing ⚠️
care/utils/ulid/ulid.py	21.42%	22 Missing ⚠️
...e/facility/management/commands/load_event_types.py	0.00%	20 Missing ⚠️
care/facility/api/viewsets/events.py	74.50%	13 Missing ⚠️
care/facility/events/handler.py	76.36%	10 Missing and 3 partials ⚠️
care/utils/ulid/models.py	60.00%	12 Missing ⚠️
care/utils/event_utils.py	66.66%	6 Missing and 4 partials ⚠️
care/facility/api/viewsets/patient.py	76.92%	4 Missing and 5 partials ⚠️
care/facility/models/events.py	80.85%	9 Missing ⚠️
care/utils/ulid/serializers.py	58.33%	5 Missing ⚠️
... and 5 more

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1891      +/-   ##
==========================================
+ Coverage   61.65%   61.88%   +0.22%     
==========================================
  Files         211      221      +10     
  Lines       11721    12149     +428     
  Branches     1664     1728      +64     
==========================================
+ Hits         7227     7518     +291     
- Misses       4196     4319     +123     
- Partials      298      312      +14     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.