fix bulk invite and query

[octavioamu]

Description

Change rule of having at least 1 skill to have at least some filter
Add option to custom search by leaderboard and bounties complete amounts

Fix admin view for invites

Refers/Fixes

https://gitcoincore.slack.com/archives/CAXQ7PT60/p1572424579194800

Testing

[codecov]

Codecov Report

Merging #5428 into master will increase coverage by 0.01%.
The diff coverage is 54.54%.

@@            Coverage Diff             @@
##           master    #5428      +/-   ##
==========================================
+ Coverage   29.83%   29.84%   +0.01%     
==========================================
  Files         241      241              
  Lines       20433    20442       +9     
  Branches     2926     2928       +2     
==========================================
+ Hits         6096     6101       +5     
- Misses      14086    14087       +1     
- Partials      251      254       +3

Impacted Files	Coverage Δ
app/dashboard/views.py	12.96% <0%> (ø)	⬆️
app/dashboard/admin.py	63.41% <60%> (-0.3%)	⬇️
...rketing/management/commands/no_applicants_email.py	0% <0%> (ø)	⬆️

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