* Guard against XCM recursive bombs by setting a recursion limit

* Add test and set a lower recursion limit

* Use u32 instead of usize for recursion limit

* Make spellcheck happy

* Cargo fmt

* Limit XCM decoding depth in UMP message processing

* Modify test to check for recursion in BuyExecution

* Update xcm/xcm-simulator/example/src/lib.rs

Co-authored-by: Kian Paimani <5588131+kianenigma@users.noreply.github.com>

* Make cargo fmt happy

* WIP for testing recursion limit in WASM

* Revert "WIP for testing recursion limit in WASM"

This reverts commit 39181b46

.

* Remove XCM recursion limit test

* Add recursion test for XCM message execution

* Set a more sensible recursion limit

* Cargo fmt

* Implement successful_origin for benchmarks

* Set recursion limit to 8 and create integration tests directory for xcm-executor

* Cargo fmt

* Add runtime-benchmarks feature to test-runtime

* Give up creating ConvertOriginToLocal and use EnsureXcm

* Re-add ConvertOriginToLocal

* Fix compilation

* Update xcm/xcm-executor/src/lib.rs

Co-authored-by: Gavin Wood <gavin@parity.io>

* Add decoding limit to all versioned XCM decode calls

* Fix recursion limit test

* Set a lower recursion count for recursion test

* move integration tests to their own folder, fix recursion check in execute_effects

* Remove xcm-executor integration tests directory

* fix up

* Update Cargo.lock

* Update runtime/parachains/src/ump.rs

* use proper decode limit

* fix decode depth limit

* here too

* Update traits.rs

* fix compile

* fix test

* Revert `decode_all_with_depth_limit` changes in parachain.rs

* Remove unused imports in parachain.rs

Co-authored-by: Keith Yeung <kungfukeith11@gmail.com>
Co-authored-by: Kian Paimani <5588131+kianenigma@users.noreply.github.com>
Co-authored-by: Bastian Köcher <info@kchr.de>
Co-authored-by: Gavin Wood <gavin@parity.io>