Statemint/e add DOT/KSM xcm

[bvotteler]

Support XCM for Statemint and Statemine:

• DOT to and from Interlay
• KSM to and from Kintsugi

[bvotteler]

Currently blocked. I am unable to manually construct an XCM message that succeeds sending DOT from interlay to statemint or the other way around.

I am in touch with Sander for advice to unblock this issue.