Migrate parachain swaps to Coretime (#3714)

This PR notifies broker pallet for any parachain slot swaps performed on
the relay chain. This is achieved by registering an `OnSwap` for the the
`coretime` pallet. The hook sends XCM message to the broker chain and
invokes a new extrinsic `swap_leases` which updates `Leases` storage
item (which keeps the legacy parachain leases).

I made two assumptions in this PR:
1.
[`Leases`](https://github.com/paritytech/polkadot-sdk/blob/4987d7982461e2e5ffe219cdf71ec697284cea7c/substrate/frame/broker/src/lib.rs#L120)
in `broker` pallet and
[`Leases`](https://github.com/paritytech/polkadot-sdk/blob/4987d7982461e2e5ffe219cdf71ec697284cea7c/polkadot/runtime/common/src/slots/mod.rs#L118)
in `slots` pallet are in sync.
2. `swap_leases` extrinsic from `broker` pallet can be triggered only by
root or by the XCM message from the relay chain. If not - the extrinsic
will generate an error and do nothing.

As a side effect from the changes `OnSwap` trait is moved from
runtime/common/traits.rs to runtime/parachains. Otherwise it is not
accessible from `broker` pallet.

Closes https://github.com/paritytech/polkadot-sdk/issues/3552

TODOs:

- [x] Weights
- [x] Tests

---------

Co-authored-by: command-bot <>
Co-authored-by: eskimor <eskimor@users.noreply.github.com>
Co-authored-by: Bastian Köcher <git@kchr.de>

prdoc/pr_3714.prdoc

@@ -0,0 +1,10 @@
+title: Handle legacy lease swaps on coretime
+
+doc:
+  - audience: Runtime Dev
+    description: |
+      When a `registar::swap` extrinsic is executed it swaps two leases on the relay chain but the
+      broker chain never knows about this swap. This change notifies the broker chain via a XCM
+      message for a swap so that it can update its state.
+crates:
+  - name: pallet-broker