Export getAccessorValue as util from library

[nickofthyme]

Is your feature request related to a problem? Please describe.
The getAccessorValue can be useful for complex accessors when the accessor value is required, in the case of formatting and filtering. As such implementing a generic helper function to facilitate such tasks would DRY up consumer code.

Describe the solution you'd like
Export getAccessorValue with built-in type assertions via generics. See example here