Add Dex pallet (#407)

* Move pallet-asset-conversion

* update licensing

* initial integration

* Integrate Currency & Assets types

* integrate liquidity tokens

* fmt

* integrate dex pallet tests

* fmt

* compilation error fixes

* integrate dex benchmarks

* fmt

* cargo clippy

* replace all occurrences of "asset" with "coin"

* add the actual add liq/swap logic to in-instructions

* add client side & tests

* fix deny

* Lint and changes

- Renames InInstruction::AddLiquidity to InInstruction::SwapAndAddLiquidity
- Makes create_pool an internal function
- Makes dex-pallet exclusively create pools against a native coin
- Removes various fees
- Adds new crates to GH workflow

* Fix rebase artifacts

* Correct other rebase artifact

* Correct CI specification for liquidity-tokens

* Correct primitives' test to the standardized pallet account scheme

---------

Co-authored-by: Luke Parker <lukeparker5132@gmail.com>

substrate/dex/primitives/Cargo.toml

@@ -0,0 +1,44 @@
+[package]
+name = "serai-dex-primitives"
+version = "0.1.0"
+description = "Dex pallet primitives"
+license = "AGPL-3.0-only"
+repository = "https://github.com/serai-dex/serai/tree/develop/substrate/dex/primitives"
+authors = ["Parity Technologies <admin@parity.io>, Akil Demir <aeg_asd@hotmail.com>"]
+edition = "2021"
+
+[package.metadata.docs.rs]
+all-features = true
+rustdoc-args = ["--cfg", "docsrs"]
+targets = ["x86_64-unknown-linux-gnu"]
+
+[dependencies]
+codec = { package = "parity-scale-codec", version = "3.6.1", default-features = false }
+scale-info = { version = "2.5.0", default-features = false, features = ["derive"] }
+
+frame-support = { git = "https://github.com/serai-dex/substrate", default-features = false }
+frame-benchmarking = { git = "https://github.com/serai-dex/substrate", default-features = false, optional = true }
+
+sp-runtime = { git = "https://github.com/serai-dex/substrate", default-features = false }
+sp-std = { git = "https://github.com/serai-dex/substrate", default-features = false }
+
+serai-primitives = { path = "../../primitives", default-features = false }
+
+[features]
+default = [ "std" ]
+std = [
+  "codec/std",
+  "scale-info/std",
+
+  "frame-support/std",
+  "frame-benchmarking?/std",
+
+  "serai-primitives/std",
+
+  "sp-runtime/std",
+  "sp-std/std",
+]
+runtime-benchmarks = [
+  "frame-benchmarking/runtime-benchmarks",
+  "frame-support/runtime-benchmarks",
+]