R4R: validator outgoing redelegations and unbonding delegations

[fedekunze]

Closes #2477

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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 entries in PENDING.md with issue #

• rereviewed 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 #2542 into develop will increase coverage by 0.04%.
The diff coverage is 66.66%.

@@             Coverage Diff             @@
##           develop    #2542      +/-   ##
===========================================
+ Coverage    60.28%   60.32%   +0.04%     
===========================================
  Files          150      150              
  Lines         8589     8613      +24     
===========================================
+ Hits          5178     5196      +18     
- Misses        3067     3069       +2     
- Partials       344      348       +4

[cwgoes]

utACK