feat(litestar): add `get_session` to plugin

[cofin]

Adds the configuration get_session and provide_session methods to the SQLAlchemyPlugin for Litestar.

[codecov-commenter]

Codecov Report

:x: Patch coverage is 30.00000% with 21 lines in your changes missing coverage. Please review. :white_check_mark: Project coverage is 79.20%. Comparing base (1932e1b) to head (46677b0). :warning: Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
...ed_alchemy/extensions/litestar/plugins/__init__.py	30.00%	21 Missing :warning:

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #461      +/-   ##
==========================================
- Coverage   79.45%   79.20%   -0.25%     
==========================================
  Files          87       87              
  Lines        6273     6301      +28     
  Branches      786      790       +4     
==========================================
+ Hits         4984     4991       +7     
- Misses       1040     1061      +21     
  Partials      249      249              

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[sonarqubecloud[bot]]

Quality Gate failed

Failed conditions
23.7% Coverage on New Code (required ≥ 80%)

See analysis details on SonarQube Cloud

[sonarqubecloud[bot]]

Quality Gate failed

Failed conditions
23.7% Coverage on New Code (required ≥ 80%)

See analysis details on SonarQube Cloud

[sonarqubecloud[bot]]

Quality Gate failed

Failed conditions
23.7% Coverage on New Code (required ≥ 80%)

See analysis details on SonarQube Cloud

[github-actions[bot]]

Documentation preview will be available shortly at https://litestar-org.github.io/advanced-alchemy-docs-preview/461