Add type hints to src/palace/manager/api/admin/ code.

[dbernstein]

Description

As part of the ongoing effort to add type hints everywhere. This PR adds type hints to everything below src/palace/manager/api/admin/ and tightens up an implementations that require changes due to type hint additions.

Motivation and Context

Long term team-wide effort.

How Has This Been Tested?

Tests pass. Mypy passes.

Checklist

• I have updated the documentation accordingly.
• All new and existing tests passed.

[codecov]

Codecov Report

❌ Patch coverage is 78.50467% with 46 lines in your changes missing coverage. Please review.
✅ Project coverage is 92.96%. Comparing base (ebb43bf) to head (d4e43d6).

Files with missing lines	Patch %	Lines
src/palace/manager/api/admin/validator.py	76.47%	5 Missing and 3 partials ⚠️
...anager/api/admin/controller/collection_settings.py	30.00%	6 Missing and 1 partial ⚠️
.../manager/api/admin/controller/metadata_services.py	41.66%	6 Missing and 1 partial ⚠️
...nager/api/admin/controller/patron_auth_services.py	36.36%	6 Missing and 1 partial ⚠️
src/palace/manager/api/admin/controller/lanes.py	60.00%	6 Missing ⚠️
...alace/manager/api/admin/controller/custom_lists.py	50.00%	4 Missing ⚠️
...e/manager/api/admin/controller/catalog_services.py	71.42%	2 Missing ⚠️
...manager/api/admin/controller/discovery_services.py	71.42%	2 Missing ⚠️
...pi/admin/password_admin_authentication_provider.py	80.00%	1 Missing and 1 partial ⚠️
src/palace/manager/api/admin/routes.py	98.75%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3046      +/-   ##
==========================================
- Coverage   93.04%   92.96%   -0.09%     
==========================================
  Files         480      480              
  Lines       43716    43798      +82     
  Branches     6027     6034       +7     
==========================================
+ Hits        40677    40715      +38     
- Misses       1968     2005      +37     
- Partials     1071     1078       +7     

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