Refactor RecipesFragment

This commit extracts SwipeRefreshLayout extension to a
separate file. Additionally, it refactors RecipesFragment in
order to move all the logic to the ViewModel from the View.

app/src/main/java/gq/kirmanak/mealient/ui/ViewExtensions.kt

@@ -0,0 +1,31 @@
+package gq.kirmanak.mealient.ui
+
+import androidx.lifecycle.LiveData
+import androidx.lifecycle.asLiveData
+import androidx.swiperefreshlayout.widget.SwipeRefreshLayout
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.channels.awaitClose
+import kotlinx.coroutines.channels.onClosed
+import kotlinx.coroutines.channels.onFailure
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.callbackFlow
+import timber.log.Timber
+
+@ExperimentalCoroutinesApi
+fun SwipeRefreshLayout.refreshesLiveData(): LiveData<Unit> {
+    val callbackFlow: Flow<Unit> = callbackFlow {
+        val listener = SwipeRefreshLayout.OnRefreshListener {
+            Timber.v("Refresh requested")
+            trySend(Unit)
+                .onFailure { Timber.e(it, "refreshesFlow: can't send refresh callback") }
+                .onClosed { Timber.e(it, "refreshesFlow: flow has been closed") }
+        }
+        Timber.v("Adding refresh request listener")
+        setOnRefreshListener(listener)
+        awaitClose {
+            Timber.v("Removing refresh request listener")
+            setOnRefreshListener(null)
+        }
+    }
+    return callbackFlow.asLiveData()
+}