SIP-229: Optimism Bridge for Synths

SIP-229 introduces an optimism bridge for synths. Based on discussion on 12-Jul SC weekly call and in light of security concerns pertaining to synth bridges, 3 paths were proposed in order to move forward and this vote is a sentiment check:

1. Activate the synth bridge, as is, with the implementation proposed in SIP-229
2. Incorporate a pDAO only function into the bridge, where only the pDAO address can bridge synths. This would be removed once security concerns are satisfied (to be addressed in a different SIP)
3. Hold off on activating the bridge until the security concerns addressed in the meeting are satisfied

Context on security concerns: a) Not having caps in place on the amounts allowed to bridge b) Using a non-standard optimism bridge contract, which increases surface area of attack, as the sequencer would be able to infinite mint synths (back to L1)