Rococo & Westend People Chain (#2281)

Rococo and Westend runtimes for the "People Chain". This chain contains
the Identity pallet with plans to migrate all related data from the
Relay Chain.

Changes `IdentityInfo` to:

- Remove `additional_fields`.
- Add `github` and `discord` as first class fields. From scraping chain
data, these were the only two additional fields used (for the Fellowship
and Ambassador Program, respectively).
- Rename `riot` to `matrix`.

Note: This will use the script in
https://github.com/paritytech/polkadot-sdk/pull/2025 to generate the
genesis state.

TODO:

- [x] https://github.com/paritytech/polkadot-sdk/pull/1814 and
integration of the Identity Migrator pallet for migration.
- [x] Tests: https://github.com/paritytech/polkadot-sdk/pull/2373

---------

Co-authored-by: Muharem <ismailov.m.h@gmail.com>
Co-authored-by: Michal Kucharczyk <1728078+michalkucharczyk@users.noreply.github.com>
Co-authored-by: Dónal Murray <donal.murray@parity.io>
Co-authored-by: Richard Melkonian <35300528+0xmovses@users.noreply.github.com>
Co-authored-by: Liam Aharon <liam.aharon@hotmail.com>

cumulus/parachains/integration-tests/emulated/networks/westend-system/src/lib.rs

@@ -17,12 +17,14 @@ pub use asset_hub_westend_emulated_chain;
 pub use bridge_hub_westend_emulated_chain;
 pub use collectives_westend_emulated_chain;
 pub use penpal_emulated_chain;
+pub use people_westend_emulated_chain;
 pub use westend_emulated_chain;
 
 use asset_hub_westend_emulated_chain::AssetHubWestend;
 use bridge_hub_westend_emulated_chain::BridgeHubWestend;
 use collectives_westend_emulated_chain::CollectivesWestend;
 use penpal_emulated_chain::{PenpalA, PenpalB};
+use people_westend_emulated_chain::PeopleWestend;
 use westend_emulated_chain::Westend;
 
 // Cumulus
@@ -38,6 +40,7 @@ decl_test_networks! {
 			AssetHubWestend,
 			BridgeHubWestend,
 			CollectivesWestend,
+			PeopleWestend,
 			PenpalA,
 			PenpalB,
 		],
@@ -50,6 +53,7 @@ decl_test_sender_receiver_accounts_parameter_types! {
 	AssetHubWestendPara { sender: ALICE, receiver: BOB },
 	BridgeHubWestendPara { sender: ALICE, receiver: BOB },
 	CollectivesWestendPara { sender: ALICE, receiver: BOB },
+	PeopleWestendPara { sender: ALICE, receiver: BOB },
 	PenpalAPara { sender: ALICE, receiver: BOB },
 	PenpalBPara { sender: ALICE, receiver: BOB }
 }