Add foundry tests for existing contracts where beneficial

[keirongulrajani]

Now that Foundry has been integrated with the code we can add tests for the existing contracts we have that will take advantage of the abilities on Foundry (such as fuzzing). We have existing javascript tests so perhaps not all tests are required to be migrated however there are definitely contracts that can benefit from fuzzing in particular (i.e. contracts dealing with math such as bonding curve/square root/lockup contract which can alter values given different states)