add integration tests to xcm-builder (#3537)

* add integration tests to xcm-builder

* add an integration test for reserve_transfer_assets

* add query holding and teleport tests

* formatting

* add to barrier doc comments and fix doc tests warnings

* use more realistic barrier for integration tests

* improve imports

* adjust base xcm weight and existential deposit to be in line with Kusama

* remove AnyNetwork

Co-authored-by: Amar Singh <asinghchrony@protonmail.com>

* add more comments and remove unnecessary code

* move mock into separate file

* reduce imports

* update cargo.lock

* remove reserve transfer test from xcm builder integration tests

* reword barrier doc comment

* elaborate on QueryHolding test scenario

* add an integration test for reserve based transfers from parachain to parachain

* add teleport tests

* fix failing teleport filter tests

* Update xcm/xcm-builder/src/integration_tests.rs

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

* Update xcm/xcm-builder/src/integration_tests.rs

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

* Update xcm/xcm-builder/src/integration_tests.rs

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

* Move integration tests to tests/ directory

* Fix merge

* Replace All wildcard with a concrete seed amount

* Rename SEED_AMOUNT to REGISTER_AMOUNT

* Fix compilation error

* Check for teleport destination first before checking out assets

* Fix unit test

* Do not run tests in integration mock

* Add a permissive assets filter for teleportation

* Remove check for teleport location in InitiateTeleport XCM

* Remove defunct test

* Apply suggestions from code review

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

* Reword comment

Co-authored-by: Amar Singh <asinghchrony@protonmail.com>
Co-authored-by: Kian Paimani <5588131+kianenigma@users.noreply.github.com>
Co-authored-by: Keith Yeung <kungfukeith11@gmail.com>