R4R: make rest-server respect persistent flags

[alessio]

The rest-server command didn't respect persistent flags such as --chain-id and --trust-node if they were passed on the command line.

• 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

---

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 #3453 into develop will decrease coverage by 0.02%.
The diff coverage is 0%.

@@             Coverage Diff             @@
##           develop    #3453      +/-   ##
===========================================
- Coverage    59.45%   59.43%   -0.03%     
===========================================
  Files          135      135              
  Lines         9981     9981              
===========================================
- Hits          5934     5932       -2     
- Misses        3675     3677       +2     
  Partials       372      372

[jackzampolin]

Lookin' good 😎 👍 LGTM

[cwgoes]

tACK