[Port][Expression]Add stringOrValue built-in function

[Danieladu]

Fixes #3281

Description

Introduce a new built-in function that refers to smart interpolation.

The original requirements are:

• when user input is a simple variable, like ${name} or ${age}, it should evaluate as a single variable and the return type is the variable type (int\float\string, it could vary)
• when user input is text + variables, like ${age} is too big, it should evaluate as a string intepolation, and always return a string type

Samples:
stringOrValue('${2+3}') -> 5
stringOrValue('woof is ${3+5}') would produce 'woof is 8'.

Changes

Create a new function that can evaluate the value expression smartly.

[coveralls]

Pull Request Test Coverage Report for Build 548915645

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 2 unchanged lines in 1 file lost coverage.
• Overall coverage decreased (-0.003%) to 84.807%

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Files with Coverage Reduction	New Missed Lines	%
libraries/adaptive-expressions/src/triggerTrees/trigger.ts	2	62.79%

Totals
Change from base Build 548915417:	-0.003%
Covered Lines:	18508
Relevant Lines:	20812

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💛 - Coveralls