chore(event-queue): update event endpoints visibility to public

[glevco]

Motivation

Currently, trying to access Event Queue endpoints on our public nodes returns 403 Forbidden. This PR updates the endpoints visibility so they can be used by clients.

Acceptance Criteria

• Change GET /event visibility to public and add rate limits (the same used by GET /feature)
• Add /event_ws websocket endpoint to nginx config, using the same parameters as /mining_ws

Checklist

• If you are requesting a merge into master, confirm this code is production-ready and can be included in future releases as soon as it gets merged

[codecov]

Codecov Report

Merging #746 (c95834d) into master (48a64d6) will increase coverage by 0.01%.
Report is 3 commits behind head on master.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #746      +/-   ##
==========================================
+ Coverage   84.54%   84.56%   +0.01%     
==========================================
  Files         252      252              
  Lines       21688    21688              
  Branches     2937     2937              
==========================================
+ Hits        18337    18341       +4     
+ Misses       2712     2709       -3     
+ Partials      639      638       -1     

Files Changed	Coverage Δ
hathor/event/resources/event.py	86.84% <ø> (ø)
hathor/feature_activation/resources/feature.py	94.04% <ø> (ø)

... and 2 files with indirect coverage changes

The base branch was changed.