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/common/src/impls.rs

@@ -244,7 +244,7 @@ macro_rules! impl_assert_events_helpers_for_relay_chain {
 					);
 				}
 
-				/// Asserts a XCM message is sent
+				/// Asserts an XCM program is sent.
 				pub fn assert_xcm_pallet_sent() {
 					$crate::impls::assert_expected_events!(
 						Self,
@@ -254,7 +254,8 @@ macro_rules! impl_assert_events_helpers_for_relay_chain {
 					);
 				}
 
-				/// Asserts a XCM from System Parachain is succesfully received and proccessed
+				/// Asserts an XCM program from a System Parachain is successfully received and
+				/// processed within expectations.
 				pub fn assert_ump_queue_processed(
 					expected_success: bool,
 					expected_id: Option<$crate::impls::ParaId>,

cumulus/parachains/integration-tests/emulated/common/src/lib.rs

@@ -32,7 +32,6 @@ use sp_runtime::{
 // Polakdot
 use parachains_common::BlockNumber;
 use polkadot_runtime_parachains::configuration::HostConfiguration;
-use xcm;
 
 // Cumulus
 use parachains_common::{AccountId, AssetHubPolkadotAuraId, AuraId};