feat: updated activity section in bounty detail

[thelostone-mc]

Description

The bounty activity section in bounty details has been cryptic and there is dead code in the js-render logic written to generate the activity.
As a funder, this makes it difficult to figure out what's happened with a bounty over the course of time

This PR

• removes dead code
• makes UI responsive + prettifys
• makes the activity more readable so that folks know what exactly happens during the bounty lifecycle

IN LIVE

AFTER THIS PR

[codecov]

Codecov Report

Merging #5551 into master will increase coverage by 0.02%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #5551      +/-   ##
==========================================
+ Coverage   30.25%   30.28%   +0.02%     
==========================================
  Files         247      247              
  Lines       21073    21073              
  Branches     3048     3048              
==========================================
+ Hits         6375     6381       +6     
+ Misses      14422    14416       -6     
  Partials      276      276

Impacted Files	Coverage Δ
app/dashboard/embed.py	31.6% <0%> (+3.44%)	⬆️

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[octavioamu]

<3

[danlipert]

Nice!