[PORT]Add abs and sqrt built-in function

[Danieladu]

Fixes #3240

Description

Add abs and sqrt prebuilt function.
Example:

abs(3.12134)  -> 3.12134
abs(-3.12134) -> 3.12134
abs(0) -> 0
sqrt(9) -> 3
sqrt(-1)  -> throw error
sqrt(0) ->  0

[coveralls]

Pull Request Test Coverage Report for Build 520218437

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.002%) to 84.713%

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Totals
Change from base Build 519010468:	0.002%
Covered Lines:	18092
Relevant Lines:	20387

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💛 - Coveralls