T13697 remove mongo from 4.0

[niden]

Hello!

• Type: temporary
• Link to issue: Remove Mongo from Phalcon #13697

In raising this pull request, I confirm the following:

• I have read and understood the Contributing Guidelines
• I have checked that another pull request for this purpose does not exist
• I wrote some tests for this PR
• I have updated the relevant CHANGELOG
• I have created a PR for the documentation about this change

Removed the mongo collection classes from v4 since they are outdated. There is already work for the new version of the mongo driver in #13697 for 4.1

Thanks

[codecov]

Codecov Report

Merging #14361 into 4.0.x will increase coverage by 1.53%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##            4.0.x   #14361      +/-   ##
==========================================
+ Coverage   66.29%   67.82%   +1.53%     
==========================================
  Files         487      477      -10     
  Lines      115843   113127    -2716     
==========================================
- Hits        76801    76732      -69     
+ Misses      39042    36395    -2647