2.3.2: Clean up, stacking, commission distribution

1. Old code removal.
2. Add ability to set commission rate (DAO).
3. Ability to stake/unstake NEAR reserve with custom pool_id (DAO).
4. Ability to transfer accumulated commission (DAO).
5. Mint USN for NEAR with a huge collateral rate for an owner only (DAO).
6. Set individual commission for different assets.

Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 edition = "2018"
 name = "usn"
-version = "2.3.1"
+version = "2.3.2"
 
 [lib]
 crate-type = ["cdylib"]