Fix invalid date format errors in certain languages

[nathanss]

Submission Review Guidelines:

• I have followed the WooCommerce Contributing Guidelines and the WordPress Coding Standards.
• I have checked to ensure there aren't other open Pull Requests for the same update/change.
• I have reviewed my code for security best practices.
• Following the above guidelines will result in quick merges and clear and detailed feedback when appropriate.

Changes proposed in this Pull Request:

The issue was happening due to moment not being able to parse the date without having the correct format informed.

I copied some code from gutenberg, mostly a map from PHP date formats and moment date formats, since it is not exposed in the module. It was needed to make it work. I plan on creating a follow-up issue to maybe have this object exposed upstream after this issue gets reviewed.

Closes #44216 .

How to test the changes in this Pull Request:

Using the WooCommerce Testing Instructions Guide, include your detailed testing instructions:

1. Switch WordPress language to Simplified Chinese (简体中文) in Settings > General.
2. Enable the new product editor at /wp-admin/admin.php?page=wc-settings&tab=advanced&section=features
3. Go to Products > Add
4. Fill name
5. Go to Pricing tab, fill a valid combination of list and sale price
6. Check "schedule sale"
7. Pick a valid combination of "from" and "to" dates.
8. You should not see a validation error.
9. Test with other languages to check for regressions.

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Significance

• Patch
• Minor
• Major

Type

• Fix - Fixes an existing bug
• Add - Adds functionality
• Update - Update existing functionality
• Dev - Development related task
• Tweak - A minor adjustment to the codebase
• Performance - Address performance issues
• Enhancement - Improvement to existing functionality

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Comment

[louwie17]

Tested well, although I rather dislike how long and convoluted the date time picker control has become. I don't know what is going on for the most part there appears to be a lot of different formatting going on.
I wonder if we can simplify it and with that just be able to make use of the format function from wordpress date.