Add more test example for build-in function

[jackwener]

Enhancement

There isn't enough test for build-in function in src/common/function/test/FunctionManagerTest.cpp.

We can add more corner case test or other test for call X build-in function .

[Aman123lug]

i am newbie in nebula i want to start working on this issue

[wey-gu]

Dear @Aman123lug , welcome to the community!

Thanks and for anything I could help let me know here or in slack :)

[AniketNS]

Hey @wey-gu can u please assign this task to me?

[AniketNS]

Thank's @wey-gu, I'm working on this.

[RAJVARDHAN2486]

Hey @wey-gu , I am newbie in this field but have strong technical knowledge , can you please assign some task for me

[wey-gu]

Awesome @RAJVARDHAN2486 !

I kept this task open for you @RAJVARDHAN2486 and I marked one hard task for you too, if you are interested in that, I can assign it to you!