feat: charge a fee for opening swap deposit addresses

[dandanlen]

Pull Request

Closes: PRO-1134

Checklist

Please conduct a thorough self-review before opening the PR.

• I am confident that the code works.
• I have updated documentation where appropriate.

Summary

Charges a fee for opening swap channels.

Currently the fee is zero, can be set using the new governance extrinsic update_pallet_config.

Bonus feature: it's now possible to do multiple updates at once (eg. update all the swap limits at once).

[dandanlen]

Kyle mentioned that it might make sense to apply the fee to all channels (swap and lp), and i agree. So i moved it into the ingress/egress pallet.

I also moved the fee to the rpcs instead of returning it in the apis.

[codecov]

Codecov Report

Attention: 29 lines in your changes are missing coverage. Please review.

Comparison is base (76ce86a) 73% compared to head (e2bd018) 73%.

❗ Current head e2bd018 differs from pull request most recent head 68704e6. Consider uploading reports for the commit 68704e6 to get more accurate results

Files	Patch %	Lines
state-chain/pallets/cf-ingress-egress/src/lib.rs	64%	14 Missing and 1 partial ⚠️
state-chain/runtime/src/lib.rs	25%	0 Missing and 6 partials ⚠️
state-chain/custom-rpc/src/lib.rs	50%	5 Missing ⚠️
state-chain/pallets/cf-swapping/src/lib.rs	70%	2 Missing and 1 partial ⚠️

Additional details and impacted files

@@          Coverage Diff           @@
##            main   #4512    +/-   ##
======================================
  Coverage     73%     73%            
======================================
  Files        401     401            
  Lines      68051   68283   +232     
  Branches   68051   68283   +232     
======================================
+ Hits       49451   49640   +189     
- Misses     15973   15978     +5     
- Partials    2627    2665    +38     

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[kylezs]

@acdibble some environment RPC snapshots changing here

[dandanlen]

Sorry @acdibble I thought you would be auto-tagged for the review. The change is an additional item channel_opening_fees in the ingress egress environment return value.

It will be set to zero initially but that might change ofc.