Fixed Model\Manager::getRelations() and getRelationsBetween()

[zsilbi]

Hello!

• Type: bug fix

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

Small description of change:

Fixed Phalcon\Mvc\Model\Manager::getRelations() and getRelationsBetween() to return many-to-many relations correctly.

Thanks,
zsilbi

[codecov]

Codecov Report

Merging #14509 into 4.0.x will increase coverage by <.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##            4.0.x   #14509      +/-   ##
==========================================
+ Coverage   67.69%   67.69%   +<.01%     
==========================================
  Files         482      482              
  Lines      111758   111763       +5     
==========================================
+ Hits        75659    75663       +4     
- Misses      36099    36100       +1

[niden]

@zsilbi When you get a chance can you rebase this please?

[niden]

Thank you @zsilbi