feat: support yyyy-mm in Datepicker

[wingkwong]

Change Summary

• closes: 🔦 Feature: columnType Date Format : add YYYY-MM #5199
• support year & month only date
  • P.S: since date type is used by default, the current day will be stored in DB but not shown in UI.
• refactor datetime utils - move those duplicate functions in frontend & backend to sdk

Change type

• feat: (new feature for the user, not a new feature for build script)
• fix: (bug fix for the user, not a fix to a build script)
• docs: (changes to the documentation)
• style: (formatting, missing semi colons, etc; no production code change)
• refactor: (refactoring production code, eg. renaming a variable)
• test: (adding missing tests, refactoring tests; no production code change)
• chore: (updating grunt tasks etc; no production code change)

Test/ Verification

Provide summary of changes.

Additional information / screenshots (optional)

Anything for maintainers to be made aware of

[github-actions]

Uffizzi Preview deployment-40857 was deleted.

[dstala]

@wingkwong IMO, we can skip this new format for dateTime & just have it for Date type.
& if we support YEAR() and MONTH() as formula's, this format could become redundant.

[wingkwong]

@wingkwong IMO, we can skip this new format for dateTime & just have it for Date type. & if we support YEAR() and MONTH() as formula's, this format could become redundant.

I plan to just have it for Date only. For DateTime, YYYY-MM HH:MM:SS seems not make any sense. Will update the code later.

[dstala]

• the following combination when tried over SQLite root DB results in invalid date
  

[dstala]

#6870 (comment)