Update getKustoDateTime with more lenient formatter

[breriksenms]

Pull Request Description

The getKustoDateTime function uses 2 potential formatters for the LocalDateTime that either include no digits for the fraction of a second or 7 digits for the fraction of a second. We ran into a situation where the value coming back from ADX had a different number of digits and would cause this method to fail. This code updates that function to just use the built-in ISO_LOCAL_DATE_TIME formatter, which allows for 0-9 digits in the fraction of a second, and appends the literal 'Z' to the end of the formatter to account for that value being present in the datetimes that ADX sends back.

---

Future Release Comment

Updating the getKustoDateTime function to use the built-in ISO_LOCAL_DATE_TIME formatter, which allows for 0-9 digits in the fraction of a second, and append the literal 'Z' to the end of the formatter to account for that value being present in the datetimes that ADX sends back.

Breaking Changes:

• None

Features:

• None

Fixes:

• Use a more lenient LocalDateTime formatter for parsing in getKustoDateTime

[xatier]

Related to #241

[ohadbitt]

Nice!

[yogilad]

We need to add additional tests for fractions and partial values before completing this PR.
If the existing formatters are not required, they need to be deleted.
Also, there are additional formats which are (probably) used for user input which do not support timezone notation

[breriksenms]

Do you have examples of the different datetime formats that you would want this method to support?

[AsafMah]

@breriksenms This PR replaces both KUSTO_DATETIME_PATTERN_NO_FRACTIONS and KUSTO_DATETIME_PATTERN
Can you test it still works with both formats at least?

Also KUSTO_DATETIME_FORMATS in CslDateTimeFormat still doesn't seem to support timezones.

[breriksenms]

I added new tests for the getKustoDateTime function that covers the different formats it supports. I'm not certain what you want to do with the KUSTO_DATETIME_FORMATS and timezones. I think that's more for sending a datetime out to Kusto, not for receiving it. Kusto only sends back datetimes in UTC timezone. The original getKustoDateTime function only supported UTC and then only in 2 formats. This PR just expands it to support a variable number of digits in the fraction of a second.

[AsafMah]

Ok, looks good!