Add datetime current date and time test case for ast builder

[heewoneha]

Goal

• Add datetime current date and time test case for ast builder

Todo

• Add datetime current date and time test case for ast builder (now())

[coveralls]

Pull Request Test Coverage Report for Build 4970513611

• 37 of 40 (92.5%) changed or added relevant lines in 1 file are covered.
• 55 unchanged lines in 2 files lost coverage.
• Overall coverage decreased (-0.2%) to 98.75%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
test-suite/src/ast_builder/function/datetime/current_date_and_time.rs	37	40	92.5%

Files with Coverage Reduction	New Missed Lines	%
core/src/executor/execute.rs	21	91.86%
core/src/executor/aggregate/mod.rs	34	82.47%

Totals
Change from base Build 4970467284:	-0.2%
Covered Lines:	43919
Relevant Lines:	44475

---

💛 - Coveralls

[panarch]

Looks all nice 👍 👍 Thanks a lot!