Fix explorer filter

[octavioamu]

Description

This pr solves some issues related to bounty explorer:

• Set applicants = all by default
• Fix bounties duplication
• Fix persist applicants election
• Fix apply parameter if applicants is in the url
• Fix on change filters collisions

Refers/Fixes

Fix #4795

Testing

Tested diff scenarios:
reset filters, query by url, change filters, reload page, reload with params, tested hackathon explorer.

[codecov]

Codecov Report

Merging #4810 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #4810   +/-   ##
=======================================
  Coverage   30.41%   30.41%           
=======================================
  Files         216      216           
  Lines       17305    17305           
  Branches     2348     2348           
=======================================
  Hits         5264     5264           
  Misses      11832    11832           
  Partials      209      209

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