Use proper bounded vector type for nominations (#10601)

* Use proper bounded vector type for nominations

* add docs and tweak chill_other for cleanup purposes

* Fix the build

* remove TODO

* add a bit more doc

* even more docs
gushc

* Update frame/staking/src/pallet/mod.rs

Co-authored-by: Zeke Mostov <z.mostov@gmail.com>

* Update frame/staking/src/pallet/mod.rs

Co-authored-by: Zeke Mostov <z.mostov@gmail.com>

* Fix the nasty bug

* also bound the Snapshot type

* fix doc test

* document bounded_vec

* self-review

* remove unused

* Fix build

* frame-support: repetition overload for bounded_vec

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* fix

* remove the need to allocate into unbounded voters etc etc

* Don't expect

* unbreal the build again

* handle macro a bit better

Co-authored-by: Zeke Mostov <z.mostov@gmail.com>
Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

substrate/frame/staking/src/lib.rs

@@ -303,6 +303,7 @@ use codec::{Decode, Encode, HasCompact};
 use frame_support::{
 	traits::{ConstU32, Currency, Get},
 	weights::Weight,
+	BoundedVec, EqNoBound, PartialEqNoBound, RuntimeDebugNoBound,
 };
 use scale_info::TypeInfo;
 use sp_runtime::{
@@ -574,10 +575,12 @@ where
 }
 
 /// A record of the nominations made by a specific account.
-#[derive(PartialEq, Eq, Clone, Encode, Decode, RuntimeDebug, TypeInfo)]
-pub struct Nominations<AccountId> {
+#[derive(PartialEqNoBound, EqNoBound, Clone, Encode, Decode, RuntimeDebugNoBound, TypeInfo)]
+#[codec(mel_bound(T: Config))]
+#[scale_info(skip_type_params(T))]
+pub struct Nominations<T: Config> {
 	/// The targets of nomination.
-	pub targets: Vec<AccountId>,
+	pub targets: BoundedVec<T::AccountId, T::MaxNominations>,
 	/// The era the nominations were submitted.
 	///
 	/// Except for initial nominations which are considered submitted at era 0.