ADR 003 follow-up

[cwgoes]

Closes #5416; see details on that issue.

---

For admin use:

• Added appropriate labels to PR (ex. WIP, R4R, docs, etc)
• Reviewers assigned
• Squashed all commits, uses message "Merge pull request #XYZ: [title]" (coding standards)

[cwgoes]

• Local mapping from memory address to name in scoped capability keeper
• Local mapping from name to index in scoped capability keeper
• Authenticate uses local mapping
• Global mapping from index to capability that can be used to claim capabilities

[cwgoes]

This may also result in making capabilities multi-owner, at least for now, that seems cleaner.

[codecov]

Codecov Report

Merging #5469 into master will increase coverage by 0.04%.
The diff coverage is 72.91%.

@@            Coverage Diff             @@
##           master    #5469      +/-   ##
==========================================
+ Coverage   54.41%   54.46%   +0.04%     
==========================================
  Files         313      313              
  Lines       18854    18892      +38     
==========================================
+ Hits        10259    10289      +30     
- Misses       7808     7812       +4     
- Partials      787      791       +4

Impacted Files	Coverage Δ
types/decimal.go	77.61% <71.05%> (+0.08%)	⬆️
types/int.go	75.59% <80%> (+0.27%)	⬆️

[alexanderbez]

ACK