Support Datetime function CURRENT_TIMESTAMP

[progress0407]

Motivation

• JDSL doesn't support CURRENT_TIMESTAMP in JPQL

Modifications

• Writing currentTimestamp() in Jpql, Expressions
• Creating a JpqlCurrentTimestampSerializer
• Add JpqlCurrentTimestampSerializer to JpqlRenderContext
• Write the respective test code
• Change FQCN for non-conventional code (*.jpql.JpqlLocalDateTimeDslTest -> *.expression.LocalDateTimeDslTest)

Commit Convention Rule

• Please commit your modification based by conventional commit:

Commit type	Description
feat	New Feature
fix	Fix bug
docs	Documentation only changed
ci	Change CI configuration
refactor	Not a bug fix or add feature, just refactoring code
test	Add Test case or fix wrong test case
style	Only change the code style(ex. white-space, formatting)
chore	It refers to minor tasks such as library version upgrade, typo correction, etc.

• If you want to add some more commit type please describe it on the Pull Request

Result

• Now supports CURRENT_TIMESTAMP.

Closes

• Support Datetime function CURRENT_TIMESTAMP #601

[shouwn]

Thanks for your contribution!

[shouwn]

The datetime and timestamp may be different in different contexts. For example, to a MySQL user, datetime and timestamp will look like separate types.

I don't think the Kotlin JDSL needs to interpret them separately and guide the user to datetime.

[shouwn]

I didn't find any other issues, so I'll fix this.

[progress0407]

Oh! Thanks, I also noticed that timestamp didn't seem to include time, so you're right!
Thanks for letting me know, that's helpful haha