Entitlement mapping composition

[SupunS]

Issue to be solved

As discussed in the FLIP onflow/flips#94, add support for including/re-using entitlement mappings in other mappings by means of 'composition'.

e.g:

entitlement mapping M1 {
    Removable -> Mutable
}

entitlement mapping M2 {
    Insertable -> Mutable
}

entitlement mapping M3 {
    include M1
    include M2
}

Suggested Solution

No response

[dsainati1]

Note for the implementation of this feature; it should interact appropriately with the changes in #2637 as described in this comment #2637 (comment)

[dsainati1]

Once this issue is complete, update the Account type file to use includes instead of repeating entitlement mappings.