Dex swap fees

[ghzlatarev]

Description

• Add a 0.5% fee for swaps where the asset-in is the native asset of the chain.
• Add a test and update benchmarks
• upstream code change: Dex swap fees Zenlink#1

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• Re-reviewed Files changed in the Github PR explorer.
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• Add A-congestion-test-checks to run start-integration-test-checks (Optional)

Situational Notes:

• If adding functionality, write unit tests!
• If importing a new pallet, choose a proper module index for it, and allow it in BaseFilter. Ensure every extrinsic works from front-end. If there's corresponding tool, ensure both work for each other.
• If needed, update our Javascript/Typescript APIs. These APIs are officially used by exchanges or community developers.
• If modifying existing runtime storage items, make sure to implement storage migrations for the runtime and test them with try-runtime. This includes migrations inherited from upstream changes, and you can search the diffs for modifications of #[pallet::storage] items to check for any.

[ferrell-code]

commented on zenlink branch