Chore/cleanup state and fees

[0xFable]

Closes #317 Closes #305 Removes some unused functions, reworks code a lil bit to accomodate changes. Made changes to fees and moved to fee.rs for custom fees too.

• [X] I have read Migaloo's contribution guidelines.
• [X] My pull request has a sound title and description (not something vague like Update index.md)
• [X] All existing and new tests are passing.
• [X] I updated/added relevant documentation.
• [X] The code is formatted properly cargo fmt --all --.
• [X] Clippy doesn't report any issues cargo clippy -- -D warnings.
• [X] I have regenerated the schemas if needed cargo schema.

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 86.36364% with 9 lines in your changes are missing coverage. Please review.

Project coverage is 88.57%. Comparing base (f1fdf5b) to head (9911660). Report is 1 commits behind head on release/v2_contracts.

Files	Patch %	Lines
packages/white-whale-std/src/fee.rs	82.97%	8 Missing :warning:
...acts/liquidity_hub/pool-manager/src/tests/suite.rs	0.00%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## release/v2_contracts #325 +/- ## ======================================================== + Coverage 88.50% 88.57% +0.07% ======================================================== Files 252 252 Lines 23602 23636 +34 ======================================================== + Hits 20888 20936 +48 + Misses 2714 2700 -14 ```

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[kerber0x]

:shipit: @0xFable