feat(withdrawal): implement fa withdrawal

[zcabter]

Context

Adds support for direct fa withdraw from external operation RunFunction and through smart function call.

Because this is implemented as smart function call, also closes https://linear.app/tezos/issue/JSTZ-112/fa-withdrawal-smart-function-call for free.

Description

This design is based on TZIP-029 except that the user initiates the withdrawal by calling the proxy smart function instead of the protocol.

This design has a few benefits over TZIP-029

1. Simpler and symmetric UX - Just like how users don't need to know the ticket details of a deposit, users should not need to know ticket details to withdraw. This information is correctly exposed in proxy smart function only.
2. Simplifies implementation in the protocol
3. Removes 1 level of indirection. It is obvious now that the proxy smart function needs to implement a withdraw bridge to withdraw their tokens

Withdraw and FA withdraw share similarities in how they are validated. The only difference between their request objects is the body, so the validate_withdraw_request was refactored with a generic <T: Deserialize>.

Doc string comments were added to TicketTable::add/sub as the return type is an ambiguous Amount

Manually testing the PR

cargo test -p jstz_proto fa_withdraw

[codecov]

Codecov Report

Attention: Patch coverage is 93.17739% with 35 lines in your changes missing coverage. Please review.

Project coverage is 36.24%. Comparing base (b6cc1bf) to head (cc627c8).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
crates/jstz_proto/src/executor/fa_withdraw.rs	93.02%	1 Missing and 14 partials ⚠️
crates/jstz_proto/src/error.rs	0.00%	13 Missing ⚠️
crates/jstz_proto/src/executor/smart_function.rs	97.67%	0 Missing and 3 partials ⚠️
crates/jstz_proto/src/executor/withdraw.rs	78.57%	0 Missing and 3 partials ⚠️
crates/jstz_core/src/kv/outbox.rs	95.00%	0 Missing and 1 partial ⚠️

Files with missing lines	Coverage Δ
crates/jstz_mock/src/lib.rs	100.00% <100.00%> (ø)
crates/jstz_proto/src/api/smart_function.rs	78.80% <100.00%> (+8.83%)	⬆️
crates/jstz_proto/src/context/ticket_table.rs	93.20% <ø> (+0.61%)	⬆️
crates/jstz_proto/src/executor/mod.rs	23.25% <ø> (ø)
crates/jstz_proto/src/receipt.rs	54.54% <ø> (ø)
crates/jstz_core/src/kv/outbox.rs	89.21% <95.00%> (+0.18%)	⬆️
crates/jstz_proto/src/executor/smart_function.rs	85.47% <97.67%> (+2.33%)	⬆️
crates/jstz_proto/src/executor/withdraw.rs	91.83% <78.57%> (-2.40%)	⬇️
crates/jstz_proto/src/error.rs	21.12% <0.00%> (+0.43%)	⬆️
crates/jstz_proto/src/executor/fa_withdraw.rs	93.02% <93.02%> (ø)

... and 1 file with indirect coverage changes

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[johnyob]

Overall lgtm 🚀

Small nit on Rust style

[johnyob]

stylistic nit: But wouldn't it make more sense to have this in an impl for FaWithdraw
e.g. FaWithdraw::execute(rt, tx, source, gas_limit)