XCM v5 (#4826)

# Context

This PR aims to introduce XCMv5, for now it's in progress and will be
updated over time.
This branch will serve as a milestone branch for merging in all features
we want to add to XCM, roughly outlined
[here](https://github.com/polkadot-fellows/xcm-format/issues/60).
More features could be added.

## TODO
- [x] Migrate foreign assets from v3 to v4
- [x] Setup v5 skeleton
- [x] Remove XCMv2
- [x] https://github.com/paritytech/polkadot-sdk/pull/5390
- [x] https://github.com/paritytech/polkadot-sdk/pull/5585
- [x] https://github.com/paritytech/polkadot-sdk/pull/5420
- [x] https://github.com/paritytech/polkadot-sdk/pull/5876
- [x] https://github.com/paritytech/polkadot-sdk/pull/5971
- [x] https://github.com/paritytech/polkadot-sdk/pull/6148
- [x] https://github.com/paritytech/polkadot-sdk/pull/6228

Fixes #3434 
Fixes https://github.com/paritytech/polkadot-sdk/issues/4190
Fixes https://github.com/paritytech/polkadot-sdk/issues/5209
Fixes https://github.com/paritytech/polkadot-sdk/issues/5241
Fixes https://github.com/paritytech/polkadot-sdk/issues/4284

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Signed-off-by: Adrian Catangiu <adrian@parity.io>
Co-authored-by: Adrian Catangiu <adrian@parity.io>
Co-authored-by: Andrii <ndk@parity.io>
Co-authored-by: Branislav Kontur <bkontur@gmail.com>
Co-authored-by: Joseph Zhao <65984904+programskillforverification@users.noreply.github.com>
Co-authored-by: Nazar Mokrynskyi <nazar@mokrynskyi.com>
Co-authored-by: Bastian Köcher <git@kchr.de>
Co-authored-by: Shawn Tabrizi <shawntabrizi@gmail.com>
Co-authored-by: command-bot <>
Co-authored-by: GitHub Action <action@github.com>
Co-authored-by: Serban Iorga <serban@parity.io>