feat: sui wtt pauser

[douglasgalico]

No description provided.

[kcsongor]

I think we should consider introducing pauser/unpauser capabilities, and guard the relevant functions behind ownership of these objects. The issue with the current method is that checking tx::sender means the pauser/unpauser can only be an EOA (and not something like the governance program or another smart contract).

Unfortunately it's not possible for the admin to then claw back a capability object from its current holder, so this approach would come with some extra complexity in the form of a table that holds which capability object is the active one (which would look a lot like the current implementation which stores the address of the pauser/unpauser. What I'm proposing would instead store the id of the pauser/unpauser cap objects, and check those instead of tx::sender)