Implement automatic ERC20 preinstall creation

All IBC tokens coming in through IBC must automatically create a canonical ERC20 contract that wraps the bank module and allows users to control their bank tokens.

Start by tracing the existing IBC token ingress and the bank-module/ERC20 integration in this Go repository. Define how canonical preinstall creation should be triggered for every incoming IBC token, then verify creation and user control of wrapped bank tokens; the issue does not name files or tests, so repository exploration is required.

Written by the indexing model from the issue text.