Make `postConditionFromMode` public

[aryzing]

Problem

@stacksjs/transactions makes both post condition mode types available as exports:

stacks.js/packages/transactions/src/postcondition-types.ts

Line 44 in fd0bf26

export type PostConditionModeName = 'allow' | 'deny';

stacks.js/packages/transactions/src/constants.ts

Line 88 in fd0bf26

export enum PostConditionMode {

but not the helper to that unifies into a single type,

stacks.js/packages/transactions/src/postcondition.ts

Line 97 in fd0bf26

export function postConditionModeFrom(

which makes it hard for clients to likewise allow for both types, and treat them in a stable manenr

Solution

Make postConditionModeFrom available for import for clients.

Additional context

Let me know if there's a better or preferred way of handling these two types, or if one will be soon deprecated?