# Description

Fixes #7413

## Integration

This PR updates the `DryRunApi`. The signature of the `dry_run_call` is
changed, and the XCM version of the return values of `dry_run_xcm` now
follows the version of the input XCM program.

## Review Notes

* **The `DryRunApi` is modified**
* **Added the `Router::clear_messages` to `dry_run_xcm` common
implementation**
* **Fixed the xcmp-queue's Router's clear_messages: channels details'
first_index and last_index are reset when clearing**
* **The MIN_XCM_VERSION is added**
* The common implementation in the `pallet-xcm` is modified accordingly
* The `DryRunApi` tests are modified to account for testing old XCM
versions
* The implementation from the `pallet-xcm` is used where it was not used
(including the `DryRunApi` tests)
* All the runtime implementations are modified according to the Runtime
API change

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Co-authored-by: Adrian Catangiu <adrian@parity.io>