add cpp example inception to nightly test

[roywei]

Description

replace #13367
a follow up to add inception into nightly test after fix in #13284

Checklist

Essentials

Please feel free to remove inapplicable items for your PR.

• The PR title starts with [MXNET-$JIRA_ID], where $JIRA_ID refers to the relevant JIRA issue created (except PRs with tiny changes)
• Changes are complete (i.e. I finished coding on this PR)
• All changes have test coverage:
• Unit tests are added for small changes to verify correctness (e.g. adding a new operator)
• Nightly tests are added for complicated/long-running ones (e.g. changing distributed kvstore)
• Build tests will be added for build configuration changes (e.g. adding a new build option with NCCL)
• Code is well-documented:
• For user-facing API changes, API doc string has been updated.
• For new C++ functions in header files, their functionalities and arguments are documented.
• For new examples, README.md is added to explain the what the example does, the source of the dataset, expected performance on test set and reference to the original paper if applicable
• Check the API doc at http://mxnet-ci-doc.s3-accelerate.dualstack.amazonaws.com/PR-$PR_ID/$BUILD_ID/index.html
• To the my best knowledge, examples are either not affected by this change, or have been fixed to be compatible with this change

Changes

• add cpp example test on inception

Comments

• If this change is a backward incompatible change, why must this change be made.
• Interesting edge cases to note here

[roywei]

@mxnet-label-bot add [pr-awaiting-testing]

[stu1130]

LGTM

[sandeep-krishnamurthy]

LGTM

[roywei]

CI passed, but found out mlp test took a long time, changed max epochs to 10 to align with mlp_gpu, mlp_cpu examples.

[lupesko]

Looks good, one issue you may have missed.

[lupesko]

You are reducing max_iters to 10, but you did not change line 152 which has an if (iter % 100 == 0)
If you want to run for 10 epochs only I think you can remove the if condition on line 152.
I also suggest to rename iter to epochNum for readability.

[roywei]

addressed comments and turns out it's iterating on a synthetic patterned data of size 128, it will take around 15000 epochs to get 90% acc. Renamed the variables and added comment