fix: Include option in getObject feature is not working

[mbfakourii]

New Pull Request Checklist

• I am not disclosing a vulnerability.
• I am creating this PR in reference to an issue.

Issue Description

fix include in get object

Closes: #813

Approach

Use Parse SDK built-in functions to solve the problem

TODOs before merging

• Add tests
• Add changes to documentation (guides, repository pages, in-code descriptions)
• A changelog entry

[parse-github-assistant]

I will reformat the title to use the proper commit message syntax.

[parse-github-assistant]

Thanks for opening this pull request!

• 🎉 We are excited about your hands-on contribution!

[codecov]

Codecov Report

Base: 13.66% // Head: 13.63% // Decreases project coverage by -0.03% ⚠️

Coverage data is based on head (f6357d8) compared to base (7dd2626).
Patch coverage: 100.00% of modified lines in pull request are covered.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #814      +/-   ##
==========================================
- Coverage   13.66%   13.63%   -0.04%     
==========================================
  Files          47       47              
  Lines        2847     2846       -1     
==========================================
- Hits          389      388       -1     
  Misses       2458     2458              

Impacted Files	Coverage Δ
packages/dart/lib/src/objects/parse_object.dart	15.41% <100.00%> (-0.38%)	⬇️

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[mtrezza]

Looks good, could you add the changelog and version bump?

[mbfakourii]

Looks good, could you add the changelog and version bump?

added

[mtrezza]

Looks good!

Edit: just noticed after merging that this should have been under "Bug Fixes" not "Features" in the changelog; I'll fix that separately.