fix(ts): reduce public type surface

[balazsorban44]

We've been re-exporting some types in multiple places, which is confusing, and also exported some internal types.

[vercel]

The latest updates on your projects. Learn more about Vercel for Git ↗︎

Name	Status	Preview	Comments	Updated (UTC)
auth-docs	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Apr 15, 2024 9:16am

1 Ignored Deployment

Name	Status	Preview	Comments	Updated (UTC)
next-auth-docs	⬜️ Ignored (Inspect)	Visit Preview		Apr 15, 2024 9:16am

[codecov]

Codecov Report

Attention: Patch coverage is 93.21429% with 19 lines in your changes are missing coverage. Please review.

Project coverage is 40.58%. Comparing base (98266d0) to head (36042c7).
Report is 84 commits behind head on main.

Files	Patch %	Lines
packages/core/src/lib/utils/assert.ts	50.00%	11 Missing ⚠️
packages/core/src/types.ts	0.00%	4 Missing ⚠️
packages/core/src/providers/oauth.ts	0.00%	2 Missing ⚠️
packages/frameworks-solid-start/src/index.ts	0.00%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #10557      +/-   ##
==========================================
+ Coverage   38.53%   40.58%   +2.05%     
==========================================
  Files         171      172       +1     
  Lines       27080    27644     +564     
  Branches     1117     1174      +57     
==========================================
+ Hits        10435    11220     +785     
+ Misses      16645    16424     -221     

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