Remove unused EmailImage entrypoint

[pgorod]

Description

We have several entry-points to get images (for Email campaigns, etc) and this one seems old and unused.

We're using others, and there seems to be an unnecessarily high number of them - download, getImage, image...

How To Test This

I couldn't find any uses of this entry-point.

I found this old PR which touches the file, but it seems accidental, the other changes don't use the file. Anyway that PR is a nice place to see which files are involved in attached email images.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Final checklist

• My code follows the code style of this project found here.
• My change requires a change to the documentation.
• I have read the How to Contribute guidelines.

[codecov-commenter]

Codecov Report

Merging #8825 into hotfix-7.10.x will increase coverage by 0.00%.
The diff coverage is n/a.

@@              Coverage Diff               @@
##           hotfix-7.10.x    #8825   +/-   ##
==============================================
  Coverage          10.69%   10.69%           
==============================================
  Files               3230     3229    -1     
  Lines             241063   241049   -14     
==============================================
  Hits               25792    25792           
+ Misses            215271   215257   -14     

[SuiteBot]

All committers have signed the CLA.

[serhiisamko091184]

Hello @pgorod ,

one more time thanks for the contribution,

Would you be so kind, make the same changes as mentioned in another PR:
#8858

Thank you very much.

Regards,
Serhii

[pgorod]

Done...

[serhiisamko091184]

Thanks for quick reply and changes!

Regards,
Serhii