ICS 29: Fee Middleware

[AdityaSripal]

Description

Implements fee middleware as specified here

closes: #XXXX

---

Before we can merge this PR, please make sure that all the following items have been
checked off. If any of the checklist items are not applicable, please leave them but
write a little note why.

• Targeted PR against correct branch (see CONTRIBUTING.md)
• Linked to Github issue with discussion and accepted design OR link to spec that describes this work.
• Code follows the module structure standards.
• Wrote unit and integration tests
• Updated relevant documentation (docs/) or specification (x/<module>/spec/)
• Added relevant godoc comments.
• Added a relevant changelog entry to the Unreleased section in CHANGELOG.md
• Re-reviewed Files changed in the Github PR explorer
• Review Codecov Report in the comment section below once CI passes

[codecov-commenter]

Codecov Report

Merging #276 (39d4c56) into main (ffa9896) will increase coverage by 0.25%.
The diff coverage is 82.96%.

@@            Coverage Diff             @@
##             main     #276      +/-   ##
==========================================
+ Coverage   79.82%   80.07%   +0.25%     
==========================================
  Files         151      166      +15     
  Lines       10907    11870     +963     
==========================================
+ Hits         8706     9505     +799     
- Misses       1776     1908     +132     
- Partials      425      457      +32     

Impacted Files	Coverage Δ
modules/apps/29-fee/types/ack.go	0.00% <0.00%> (ø)
modules/core/04-channel/types/packet.go	67.56% <0.00%> (-14.40%)	⬇️
modules/core/04-channel/types/version.go	100.00% <ø> (ø)
modules/apps/29-fee/module.go	54.38% <54.38%> (ø)
modules/apps/29-fee/types/codec.go	70.00% <70.00%> (ø)
modules/apps/29-fee/keeper/msg_server.go	75.00% <75.00%> (ø)
modules/apps/29-fee/keeper/grpc_query.go	77.68% <77.68%> (ø)
modules/apps/29-fee/keeper/escrow.go	80.00% <80.00%> (ø)
modules/apps/29-fee/types/fee.go	83.01% <83.01%> (ø)
modules/apps/29-fee/types/genesis.go	84.78% <84.78%> (ø)
... and 7 more

[damiannolan]

🚀

[fedekunze]

first pass

[fedekunze]

I don't understand this comment, can you elaborate?

[fedekunze]

why cosmos-sdk? Is amino support required?

[fedekunze]

nit, split lines

[fedekunze]

can you use the one from the transfer or channel module?

[fedekunze]

why not return an error immediately instead of appending it?

[seantking]

Multiple fees may be invalid I think it's good to let the user know. I would prefer to leave as is.

[fedekunze]

Suggested change

	hasRefundAcc := k.authKeeper.GetAccount(ctx, refundAcc)
	if hasRefundAcc == nil {
	refundAcc := k.authKeeper.GetAccount(ctx, refundAcc)
	if refundAcc == nil {

[fedekunze]

Suggested change

	return sdkerrors.Wrapf(types.ErrRefundAccNotFound, "account with address: %s not found", refundAcc)
	return sdkerrors.Wrapf(types.ErrRefundAccNotFound, "account with address: %s not found", packetFee.RefundAddress)

[fedekunze]

nit, add comment to explain this in more detail

[fedekunze]

utACK, will review in detail soon