[kairos] add Flow.scanTo utilities

import kotlinx.coroutines.flow.SharedFlow

import kotlinx.coroutines.flow.StateFlow

import kotlinx.coroutines.flow.dropWhile

import kotlinx.coroutines.flow.scan

import kotlinx.coroutines.launch

/** A function that modifies the FrpNetwork. */

    @ExperimentalFrpApi

    fun <A> Flow<A>.toTState(initialValue: A): TState<A> = toTFlow().hold(initialValue)

    /**

     * Shorthand for:

     * ```kotlin

     * flow.scan(initialValue, operation).toTFlow().hold(initialValue)

     * ```

     */

    @ExperimentalFrpApi

    fun <A, B> Flow<A>.scanToTState(initialValue: B, operation: (B, A) -> B): TState<B> =

        scan(initialValue, operation).toTFlow().hold(initialValue)

    /**

     * Shorthand for:

     * ```kotlin

     * flow.scan(initialValue) { a, f -> f(a) }.toTFlow().hold(initialValue)

     * ```

     */

    @ExperimentalFrpApi

    fun <A> Flow<(A) -> A>.scanToTState(initialValue: A): TState<A> =

        scanToTState(initialValue) { a, f -> f(a) }

    /**

     * Invokes [block] whenever this [TFlow] emits a value. [block] receives an [FrpBuildScope] that

     * can be used to make further modifications to the FRP network, and/or perform side-effects via