chore(feature-activation): update feature endpoint visibility to public

[glevco]

Motivation

Currently, trying to access Feature Activation endpoints on our public nodes returns 403 Forbidden, like on https://node1.mainnet.hathor.network/v1a/feature. This PR updates the endpoint visibility so it can be used by the Hathor Explorer UIs.

Acceptance Criteria

• Change GET /feature visibility to public and add rate limits (the same used by GET /transaction)

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 #743 (0d44bb5) into master (e710e6d) will increase coverage by 0.11%.
Report is 7 commits behind head on master.
The diff coverage is 91.66%.

❗ Current head 0d44bb5 differs from pull request most recent head 4e97384. Consider uploading reports for the commit 4e97384 to get more accurate results

@@            Coverage Diff             @@
##           master     #743      +/-   ##
==========================================
+ Coverage   84.43%   84.55%   +0.11%     
==========================================
  Files         251      252       +1     
  Lines       21607    21688      +81     
  Branches     2923     2937      +14     
==========================================
+ Hits        18244    18338      +94     
+ Misses       2724     2712      -12     
+ Partials      639      638       -1     

Files Changed	Coverage Δ
hathor/feature_activation/resources/feature.py	94.04% <ø> (ø)
hathor/transaction/block.py	95.35% <ø> (ø)
hathor/p2p/states/utils.py	62.50% <62.50%> (ø)
hathor/p2p/states/ready.py	93.93% <97.50%> (+1.54%)	⬆️
hathor/conf/settings.py	97.16% <100.00%> (+0.08%)	⬆️
hathor/consensus/consensus.py	97.89% <100.00%> (+0.04%)	⬆️
hathor/manager.py	82.68% <100.00%> (ø)
hathor/p2p/messages.py	100.00% <100.00%> (ø)
hathor/p2p/protocol.py	93.04% <100.00%> (+0.05%)	⬆️
hathor/p2p/states/hello.py	72.00% <100.00%> (+0.28%)	⬆️
... and 2 more

... and 6 files with indirect coverage changes