refactor: move simulator utils functions

[glevco]

Motivation

The events simulator CLI tool was using some functions defined in the tests module, which is not copied to the Docker image. To make the tool available via Docker, those functions must be moved to another module.

Acceptance Criteria

• Move functions from tests module to utils/simulator module
• Update imports
• Add custom check to make sure tests are not imported in hathor
• Small changes to fix linter issues with added typings

Checklist

• If you are requesting a merge into master, confirm this code is production-ready and can be included in future releases as soon as it gets merged

[codecov]

Codecov Report

Attention: 1 lines in your changes are missing coverage. Please review.

Comparison is base (769d255) 85.16% compared to head (5a38b60) 85.22%.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #772      +/-   ##
==========================================
+ Coverage   85.16%   85.22%   +0.06%     
==========================================
  Files         284      285       +1     
  Lines       22576    22655      +79     
  Branches     3430     3444      +14     
==========================================
+ Hits        19226    19308      +82     
  Misses       2667     2667              
+ Partials      683      680       -3     

Files	Coverage Δ
hathor/simulator/tx_generator.py	96.05% <100.00%> (ø)
hathor/simulator/utils.py	98.73% <98.73%> (ø)

... and 4 files with indirect coverage changes

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[jansegre]

Looks good to me. Two minor points:

• This should probably be named a refactor;
• Should we add a linter check to prevent from tests* import or import tests*?

[glevco]

• This should probably be named a refactor;
• Should we add a linter check to prevent from tests* import or import tests*?

@jansegre both done!

[glevco]

Converted to draft as we wait other PRs to be merged before this one.