[Feature] add a flag to the rest server to accept all cors

[yun-yeo]

Summary of changes

• added a flag to the rest server that if you are fine with accepting all cors you can.

close #409

Report of required housekeeping

• Github issue OR spec proposal link
• Wrote tests
• Updated API documentation (client/lcd/swagger-ui/swagger.yaml)
• Added a relevant changelog entry: clog add [section] [stanza] [message]

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(FOR ADMIN) Before merging

• Added appropriate labels to PR
• Squashed all commits, uses message "Merge pull request #XYZ: [title]" (coding standards)
• Confirm added tests are consistent with the intended behavior of changes
• Ensure all tests pass

[codecov]

Codecov Report

Merging #420 into develop will decrease coverage by 0.03%.
The diff coverage is n/a.

@@             Coverage Diff             @@
##           develop     #420      +/-   ##
===========================================
- Coverage    67.55%   67.51%   -0.04%     
===========================================
  Files          117      117              
  Lines         5051     5051              
===========================================
- Hits          3412     3410       -2     
- Misses        1426     1427       +1     
- Partials       213      214       +1     

Impacted Files	Coverage Δ
x/oracle/tally.go	88.37% <0.00%> (-4.66%)	⬇️