Replace webpub manifest parser with pydantic (PP-1367)

[jonathangreen]

Description

Replace our custom web manifest parser with Pydantic models.

I replace the validation we were doing via a patched json schema with the pydantic parser, since it gives better errors and more closely matches what we are expecting in Palace.

Edit: I broke this one into two PRs to make it a little easier to review. This PR actually implements the new models in our existing code, #2168 adds the models.

Motivation and Context

JIRA: PP-1367

Note: After this one goes in we should cut a new release of https://github.com/ThePalaceProject/webpub-manifest-parser and then mark it as archived, since we won't be using it anymore.

How Has This Been Tested?

• Ran unit tests
• Imported some feeds locally:
  • Test Palace Marketplace feed
  • Palace Bookshelf feed

Checklist

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

[codecov]

Codecov Report

Attention: Patch coverage is 92.08633% with 11 lines in your changes missing coverage. Please review.

Project coverage is 90.91%. Comparing base (399768d) to head (da3e71a).

Files with missing lines	Patch %	Lines
src/palace/manager/core/opds2_import.py	90.12%	4 Missing and 4 partials ⚠️
src/palace/manager/util/__init__.py	71.42%	0 Missing and 2 partials ⚠️
src/palace/manager/api/odl/importer.py	96.55%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@                         Coverage Diff                          @@
##           feature/add-pydantic-opds-models    #2163      +/-   ##
====================================================================
+ Coverage                             90.79%   90.91%   +0.12%     
====================================================================
  Files                                   359      359              
  Lines                                 41294    41171     -123     
  Branches                               8924     8885      -39     
====================================================================
- Hits                                  37492    37432      -60     
+ Misses                                 2481     2429      -52     
+ Partials                               1321     1310      -11     

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