Implement initialize_token

[td202]

Purpose

Part of RUN-15

Implement the initialize_token operation in the rust runtime.

Changes

• HostOperations: AccountAddress and Account passed by reference.
• Add HostOperationsExt trait that provides set_module_state.
• Implement initialize_token.

Checklist

• My code follows the style of this project.
• The code compiles without warnings.
• I have performed a self-review of the changes.
• I have documented my code, in particular the intent of the
  hard-to-understand areas.
• (If necessary) I have updated the CHANGELOG.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 24.98%. Comparing base (166c10b) to head (26dc3aa).
⚠️ Report is 13 commits behind head on feature/plt-scheduler-port.

Additional details and impacted files

@@                     Coverage Diff                     @@
##           feature/plt-scheduler-port    #1465   +/-   ##
===========================================================
  Coverage                       24.98%   24.98%           
===========================================================
  Files                              34       34           
  Lines                           10203    10203           
===========================================================
  Hits                             2549     2549           
  Misses                           7654     7654           

[github-actions]

The file size of the WebAssembly PLT deployment unit is 278155B.

[limemloh]

Looks good to me

[td202]

Why do I have to write something here?