⚡ (openai) Add Messages sequence type

To make it easy to just plug a sequence of user / assistant messages to Chat completion task

Closes #387

apps/viewer/src/features/chat/api/utils/continueBotFlow.ts

@@ -103,7 +103,12 @@ const saveVariableValueIfAny =
     if (!foundVariable) return state
 
     const newSessionState = await updateVariables(state)([
-      { ...foundVariable, value: reply },
+      {
+        ...foundVariable,
+        value: Array.isArray(foundVariable.value)
+          ? foundVariable.value.concat(reply)
+          : reply,
+      },
     ])
 
     return newSessionState

apps/viewer/src/features/chat/api/utils/executeGroup.ts

@@ -124,15 +124,12 @@ const computeRuntimeOptions =
 
 const getPrefilledInputValue =
   (variables: SessionState['typebot']['variables']) => (block: InputBlock) => {
-    return (
-      variables
-        .find(
-          (variable) =>
-            variable.id === block.options.variableId &&
-            isDefined(variable.value)
-        )
-        ?.value?.toString() ?? undefined
-    )
+    const variableValue = variables.find(
+      (variable) =>
+        variable.id === block.options.variableId && isDefined(variable.value)
+    )?.value
+    if (!variableValue || Array.isArray(variableValue)) return
+    return variableValue
   }
 
 const parseBubbleBlock =