chore: remove cw20 support from vault manager

[kerber0x]

Description and Motivation

This PR removes the cw20 support from the vault manager 🌟 .

Related Issues

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Checklist:

• [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)
• [ ] 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 86.18785% with 50 lines in your changes are missing coverage. Please review.

Project coverage is 88.20%. Comparing base (6850e45) to head (eabfd9b). Report is 1 commits behind head on release/v2_contracts.

Files	Patch %	Lines
packages/white-whale-std/src/coin.rs	28.57%	30 Missing :warning:
...es/white-whale-std/src/multi_test/stargate_mock.rs	64.10%	14 Missing :warning:
packages/white-whale-std/src/lp_common.rs	66.66%	2 Missing :warning:
...quidity_hub/pool-manager/src/liquidity/commands.rs	50.00%	1 Missing :warning:
.../liquidity_hub/vault-manager/tests/common/suite.rs	91.66%	1 Missing :warning:
...s/liquidity_hub/vault-manager/tests/integration.rs	98.93%	1 Missing :warning:
packages/white-whale-std/src/tokenfactory/burn.rs	95.00%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## release/v2_contracts #288 +/- ## ======================================================== - Coverage 88.25% 88.20% -0.06% ======================================================== Files 249 250 +1 Lines 23823 23424 -399 ======================================================== - Hits 21025 20660 -365 + Misses 2798 2764 -34 ```

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