Auxiliary Functionality for Genesis Accounts

[alexanderbez]

Auxiliary type(s) and function(s) that used to exist in x/genaccounts that are needed for apps to define and use their own genesis accounts.

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• Targeted PR against correct branch (see CONTRIBUTING.md)

• Linked to github-issue with discussion and accepted design OR link to spec that describes this work.

• Wrote tests

• Updated relevant documentation (docs/)

• Added a relevant changelog entry to the Unreleased section in CHANGELOG.md

• Re-reviewed Files changed in the github PR explorer

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For Admin Use:

• Added appropriate labels to PR (ex. wip, ready-for-review, docs)
• Reviewers Assigned
• Squashed all commits, uses message "Merge pull request #XYZ: [title]" (coding standards)

[codecov]

Codecov Report

Merging #5042 into master will increase coverage by 0.05%.
The diff coverage is 88.88%.

@@            Coverage Diff             @@
##           master    #5042      +/-   ##
==========================================
+ Coverage   54.95%   55.01%   +0.05%     
==========================================
  Files         290      291       +1     
  Lines       17805    17819      +14     
==========================================
+ Hits         9785     9803      +18     
+ Misses       7314     7309       -5     
- Partials      706      707       +1