Ar/psr 22 implement token module queries

[allanbrondum]

Purpose

General cleanup of traits and types to prepare for more functionality (queries, transfers, mint, ...)

Changes

• make TokenRawAmount a newtype for better type check
• generally renamed "host" to "kernel", since that is more descriptive of what we actually build (where the host interface will be, if ever introduced, is not decided)
• HostOperations split up in TokenKernelQueries and TokenKernelOperations. The former to be used when running queries, which are read-only and don't have a transaction context (like tick energy and log token event)
• Make TokenInitializationError error variants more strongly types (MintAmountDecimalsMismatch and MintAmountNotRepresentable variants) for better type checking of error handling

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 25.68%. Comparing base (660fe2b) to head (a418c8f).
⚠️ Report is 2 commits behind head on feature/plt-scheduler-port.

Additional details and impacted files

@@                      Coverage Diff                       @@
##           feature/plt-scheduler-port    #1483      +/-   ##
==============================================================
- Coverage                       26.03%   25.68%   -0.35%     
==============================================================
  Files                              34       34              
  Lines                            9830     9830              
==============================================================
- Hits                             2559     2525      -34     
- Misses                           7271     7305      +34     

see 3 files with indirect coverage changes

[allanbrondum]

Simplified the interface to stub accounts a bit

[allanbrondum]

Rewrote tests to use updated stub (small changes) and added an additional test: test_initialize_token_non_existing_governance_account

[soerenbf]

looks good