XCMv5: add ExecuteWithOrigin instruction (#6304)

Added `ExecuteWithOrigin` instruction according to the old XCM RFC 38:
https://github.com/polkadot-fellows/xcm-format/pull/38.

This instruction allows you to descend or clear while going back again.

## TODO
- [x] Implementation
- [x] Unit tests
- [x] Integration tests
- [x] Benchmarks
- [x] PRDoc

## Future work

Modify `WithComputedOrigin` barrier to allow, for example, fees to be
paid with a descendant origin using this instruction.

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Signed-off-by: Adrian Catangiu <[email protected]>
Co-authored-by: Adrian Catangiu <[email protected]>
Co-authored-by: Andrii <[email protected]>
Co-authored-by: Branislav Kontur <[email protected]>
Co-authored-by: Joseph Zhao <[email protected]>
Co-authored-by: Nazar Mokrynskyi <[email protected]>
Co-authored-by: Bastian Köcher <[email protected]>
Co-authored-by: Shawn Tabrizi <[email protected]>
Co-authored-by: command-bot <>