Initial Polygon state L2<->L1 sync contract updates

[0xFlicker]

• Replace custom access roles / ownable with OpenZeppelin AccessControls
• Add whitelist with access controls
• Minting will only be on Matic chain
• FxStateSync implementation keeps L1 tokenCount and baseUri in sync
• POS Bridge implementation to allow tokens to move between L2 and L1
• pack/unpack of token count and baseUri to/from bytes for state transfer
• Removal of LifecycleManager. It was a dumb contract.
• Storage of baseURI as bytes to reduce gas costs on state syncs. tokenURI reads are currently "free" so move calculations to the reads of converting bytes to base58 string
• Adds contract verification support

Some tests updated.

• [x] Deployer needs more work.
• [x] Backend needs to be updated.
• [x] Frontend updated TODO: Add bridging, cross-chain view to frontend