fix(IgxGrid): Fix event args for rowAdded too. Update test.

[MayaKirova]

Closes #13986

Additional information (check all that apply):

• [x] Bug fix
• [ ] New functionality
• [ ] Documentation
• [ ] Demos
• [ ] CI/CD

Checklist:

• [x] All relevant tags have been applied to this PR
• [x] This PR includes unit tests covering all the new code (test guidelines)
• [ ] This PR includes API docs for newly added methods/properties (api docs guidelines)
• [ ] This PR includes feature/README.MD updates for the feature docs
• [ ] This PR includes general feature table updates in the root README.MD
• [ ] This PR includes CHANGELOG.MD updates for newly added functionality
• [ ] This PR contains breaking changes
• [ ] This PR includes ng update migrations for the breaking changes (migrations guidelines)
• [ ] This PR includes behavioral changes and the feature specification has been updated with them

[IMinchev64]

Are the additional commits in the PR intentional?

[dkamburov]

@IMinchev64 they are due to the changing the base branch, we are going to squash merge, so you can ignore them. Please let me know if some of the changes is merged incorrectly or you are seeing some issue?