Migrations should support readonly arrays for createType().asEnum()

[matthew-holder-revvity]

This is a common way to generate enum unions by some that provides a list of the values for runtime checking.

export const ProcessType = ['develop', 'test', 'qa', 'relese'] as const
export type ProcessType = (typeof ProcessType)[number]

Unfortunately, the example ProcessType cannot be passed to createType().asEnum() since it is a read-only array and results in:

Argument of type 'readonly ['develop', 'test', 'qa', 'relese']' is not assignable to parameter of type 'string[]'.
  The type 'readonly ['develop', 'test', 'qa', 'relese']' is 'readonly' and cannot be assigned to the mutable type 'string[]'. ts(2345)

I suspect asEnum does not mutate the passed array and could except readonly arrays.

[koskimas]

Yep, we should do that.