[Fixes #12841] Add avatar templates, changing default from django-avatar to geonode-base

[cmotadev]

This PR is to correct a little template breaker into GeoNode. In the Profile Editor, Change Avatar, when we click on change button, it renders a simple HTML page. This page is a django-avatar default template. With some little modifications, these pages now are with geonode template and some additional links, like "go back to profile editor", "delete avatar"...

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 67.97%. Comparing base (0258939) to head (aa4bbd8).
Report is 1 commits behind head on master.

Additional details and impacted files

@@             Coverage Diff             @@
##           master   #12842       +/-   ##
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+ Coverage   55.87%   67.97%   +12.10%     
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  Files         977      977               
  Lines       59035    59038        +3     
  Branches     6897     6897               
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+ Hits        32984    40132     +7148     
+ Misses      24669    17263     -7406     
- Partials     1382     1643      +261