refactor: Remove SQLx crate from torii-core

[cmackenzie1]

This commit removes the sqlx crate from torii-core and removes the Error variant Database. Storages crates should use Storage variant instead.

I also moved the OAuthStorage trait out of torii-storage-sqlite and into torii-core to match the same structure as torii-auth-email

[codecov]

Codecov Report

Attention: Patch coverage is 57.56098% with 87 lines in your changes missing coverage. Please review.

Project coverage is 68.78%. Comparing base (dde8ee1) to head (368490e).
Report is 1 commits behind head on main.

✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
torii-storage-sqlite/src/lib.rs	44.59%	82 Missing ⚠️
torii-auth-oauth/src/lib.rs	16.66%	5 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #10      +/-   ##
==========================================
- Coverage   69.60%   68.78%   -0.82%     
==========================================
  Files          11       11              
  Lines        1622     1746     +124     
==========================================
+ Hits         1129     1201      +72     
- Misses        493      545      +52     

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