Guardian

[owsley3]

Adds a secondary ownership role within Prisma, the guardian

The guardian is intended to be a multisig comprised of known, prominent members of the defi community. It has the authority to:

• pause protocol operations (in case of a critical exploit)
• block the execution of DAO votes (in case of a malicious vote that achieves quorum)

If the guardian acts maliciously, the DAO can vote to change or remove them - and the guardian cannot block this vote.