Makes the contracts more lenient in the version
of solc that they can compile with, makes it easier
to begin porting the hardhat based tests to `foundry`.

Adds deployment artifacts for our Kovan deployment of the NFT bridge and
all related proxy contracts. Also includes an update to
contracts-bedrock to properly export contract sources.
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>