Backport of #240 to fix memory leaks in Image.

[peci1]

🦟 Bug fix

Fixes gazebosim/gz-gui#341 .

Summary

#240 contains a lot of fixes for Image, but was only merged to ign-common4. This PR backports it into 3.

Checklist

• Signed all commits for DCO
• Added tests
• Updated documentation (as needed)
• Updated migration guide (as needed)
• codecheck passed (See contributing)
• All tests passed (See test coverage)
• While waiting for a review on your PR, please help review another open pull request to support the maintainers

Note to maintainers: Remember to use Squash-Merge and edit the commit message to match the pull request summary while retaining Signed-off-by messages.

[codecov]

Codecov Report

Merging #287 (926580a) into ign-common3 (6d6b9d5) will increase coverage by 0.02%.
The diff coverage is 100.00%.

@@               Coverage Diff               @@
##           ign-common3     #287      +/-   ##
===============================================
+ Coverage        76.55%   76.58%   +0.02%     
===============================================
  Files               73       73              
  Lines            10387    10403      +16     
===============================================
+ Hits              7952     7967      +15     
- Misses            2435     2436       +1     

Impacted Files	Coverage Δ
graphics/src/Image.cc	68.75% <100.00%> (+1.66%)	⬆️

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