Define proper XCM Transact call filter

[sea212]

Implement a custom call filter that implements Contains that will be used for XcmConfig's configuration value SafeCallFilter. The call filter should only return true only for calls that meet the following conditions:

1. Don't lead to recursion
2. Have a fixed weight
3. Cannot lead to another call being made (i.e. utility)
4. Have a defined proof size weight, e.g. no unbounded vecs in call parameters.

for all other calls, return false.