fix(nocodb): handle comparing a date with empty string in pg

[wingkwong]

Change Summary

ref: #4546

The correct way to compare with Date should be using IS_AFTER, IS_BEFORE, or IS_SAME which are not supported at this moment. This PR is to prevent empty data returned to UI due to incorrect SQL following Airtable logic.

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

IF({DatePaid} == "", "Paid", "Not paid")

IF({DatePaid} != "", "Paid", "Not paid")
IF({DatePaid} > "", "Paid", "Not paid")
IF({DatePaid} > "123", "Paid", "Not paid")

[github-actions]

Uffizzi Preview deployment-8685 was deleted.