Added recovery after invalid cell edit for adding a new cell.

[smartguest]

This PR allows for the new row to be added again in case a user enters an invalid string. The fixes in this PR prevent multiple cell submissions from happening at the same time, and also restores the last entered string of a user after reverting the new row created (revert is required for new row addition to work once again).

Partial implementation of the edit data fixes (meant to work with the existing structure)

[alanrenmsft]

please add gif to compare the differences

[coveralls]

Pull Request Test Coverage Report for Build 3199760896

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 42.353%

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Totals
Change from base Build 3199240083:	0.0%
Covered Lines:	29381
Relevant Lines:	64547

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💛 - Coveralls

[smartguest]

Insiders:

My branch: (note the dirty status of the first cell of the new row is not marked, but this is visual only and the row will be reverted once the user presses escape (all of it for now). )