ERC20 support

[cf19drofxots]

The work to support ERC20 tokens will be tracked by this issue.

Note that the first iteration of ERC20 token functionality will support only one token to keep scope necessarily smaller. Following iteration will expand upon this scope.

The main action items (in order of execution) for this to become functional are:

• [x] 0) Ensuring the appropriate testing environment exists with an ERC20 token being minted such that it can be used to verify depositing (task 1) and withdrawal (task 2) functionality. Once these are confirmed, we can safely proceed to confirm functionality for item 3 (app installs and uninstalls work with ERC20).

  • PR: https://github.com/counterfactual/monorepo/pull/1671

• [x] 1) Need to ensure ERC20 deposits are supported

  • PR: https://github.com/counterfactual/monorepo/pull/1827

• [x] 2) Need to ensure ERC20 withdrawals are supported

  • This includes updating the withdraw API to be able to refer to an already-deposited token as a parameter for withdrawal
  • PR: https://github.com/counterfactual/monorepo/pull/1830

• [x] 3) Need to ensure ERC20 app installs are supported

  • This includes updating the proposeInstall API to be able to take in an already-deposited token as a parameter for installation.
  • Note that uninstalls do not need to take in a parameter for specifying a token because...that doesn't make sense.
  • PR: https://github.com/counterfactual/monorepo/pull/1841

• [ ] 4) ERC20 funding for virtual app installs is conditional upon the work being done here: https://github.com/counterfactual/monorepo/pull/1855

[ArjunBhuptani]

Any updates on this @cf19drofxots? We're blocked by this now